Glossary 42 Building Blocks of Text-Based Virtual Environments

金钱与幸福的英语作文Does money equal to happiness?There is so much discussion on the relationship between money and happiness. Absolutely, money is a necessary condition for a happy life, but money does not mean that the happiness.In someone’s eyes ,money can buy everything ,its charm and function has exceeded its true value and the meaning of existence . We have to admit the truth that money can buy lots of things even health .In nowadays ,a poor family shall have to live a hard life .The poor people even cant afford to children’s schooling ,no mention to the house in big city . As far as I’m concerned,having money does not mean that possession of happiness.Happiness is a kind of feeling .You could earn money by hardworking and struggling ,but you can’t get happiness only through money .(138词)有钱就能幸福吗关于金钱与幸福的关系，有太多的讨论与关注。

Glossaryabdomenabsorptionacid rain active transportadaptation aerobic respiration alimentary canalallelealveoliamino acidamnionamniotic fluidamylaseanaemia lower part of the body in humans, between the ribs and hip bonesmovement of digested food molecules through the wall of the intestine into the blood or lymphAir pollution produced when acid chemicals are incorporated into rain, snow, fog or mist. The "acid" in acid rain comes from sulfur oxides and nitrogen oxides, products of burning coal and other fuels and from certain industrial processes.movement of ions in or out of a cell through the cell membrane, from a region of their lower concentration to a region of their higher concentration against a concentration gradient, using energy released during respirationfeatures of living things that help them survive in their environmentthe release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygenthe passage along which food passes through the body, from mouth to anusone of two or more alternative forms of a geneair sacs in the lungs through which gas exchange takes placethe basic building block of proteinsthe innermost membrane enclosing the embryothe fluid surrounding the developing fetus that is found within the amniotic sac contained in the mother's womb a digestive enzyme, produced largely by the pancreas and salivary glands, which converts starches to sugars below normal levels of red blood cells or haemoglobin, or both, which can be caused by many different conditions, including iron deficiencyanaerobic respirationanther antibioticantioxidantanusaortaartery arteriole the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen pollen-producing oval body at the tip of a stamena class of natural and synthetic compounds that inhibit the growth of, or kill, other micro-organismsa molecule that is capable of reacting with free radicals and neutralising themthe opening to the anal canalthe largest artery; it leaves the heartblood vessel that carries blood away from the heart small, elastic blood vessel that arises from arteries and leads into capillariesartificial selection selective breedingasexual reproduction assimilationatomauxinaxonbacteriabilebile ductbile saltsbinomialbiodegradable the process resulting in the production of genetically identical offspring from one parentmaking use of molecules that have been absorbed from fooda chemical unit that is the smallest particle of an element still retaining its propertiesa type of plant hormone that elongates cells in seedlings, shoot tips, embryos and leavespart of a neurone that allows electrical signals to pass throughvery small single-celled organismsa liquid produced by the liver that helps in digestion of fatsthe passage from the liver to the duodenumsalts in the bile that help break fat into tiny dropletsa system in which the scientific name of an organism is made up of two parts showing the genus and species able to be broken down by bacteria and other micro-organismsbiomassbolusbronchibronchiolescaninescapillaries carbohydrase carbon dioxidecarnivorecatalystcell wallcellcervix chlorophyll chloroplasts chromosome ciliary muscles codominantcolon community concentrationgradientconesconsumer the mass of a living organisma ball of foodtubes through which air passes, between the trachea and the smaller bronchiolessmall tubes that branch from each of the bronchi pointed teeth used for bitingtiny blood vesselsenzyme that digests carbohydrategas produced during respiration and used up during photosynthesisan animal that gets its energy by eating other animalsa substance that speeds up a chemical reaction and is not changed by the reactionthe outer part of a plant cell, made of cellulosethe basic ‘building block’ of living thingsthe neck of the wombgreen pigment in plants, involved in photosynthesis structures containing chlorophylla thread of DNA, made up of a string of genesring of muscles holding the eye lensalleles both having an effect in a heterozygous organism first part of the large intestineall the different species in a habitata difference in concentration across a materiallight-sensitive cells in the retina, responsible for colour visionan organism that gets its energy by feeding on other organismscontractioncorneacoronary heartdisease coronary arteriescrustaceanscytoplasmdeaminationdecomposersdeficiency diseasedenaturingdendritesdenitrifying bacteriadialysisdiaphragmdiffusiondigestiondiploid nucleusDNAdominant double circulatorysystem in muscle tissue, the shortening of cellsthe front of the eye, responsible for most of the focusing disease in which the coronary arteries get blocked or damagedarteries that deliver blood to the heart musclesa group of arthropods including crabs, shrimp and woodlicejelly-like substance in cellsremoval of nitrogen from amino acidsan organism that gets its energy from dead or waste organic matterdisease caused by lack of a particular nutrient breakdown of an enzyme caused by a high temperature threads of cytoplasm in a neurone that pick up electrical signalsbacteria that turn ammonia and nitrates back to nitrogen filtering a patient’s blood in a similar way to a kidney muscular sheet below the ribs and lungsthe net movement of molecules from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movementthe breakdown of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processesa nucleus containing two sets of chromosomes (e.g. in body cells)deoxyribonucleic acid, the molecule from which genes are composedan allele that is expressed if it is present (e.g. T or G)a system in which the blood goes through the heart twicedrugduodenumecosystemeffectorsegestionembryoemphysema endocrine systemenzymesepidermis eutrophicationevolutionexcretionexoskeletonfaeces Fallopian tubefatty acidsfertilisationfetusfibre any substance taken into the body that modifies or affects chemical reactions in the bodyfirst part of the small intestinea unit containing all of the organisms and their environment, interacting together, in a given area e.g. decomposing log or a lakeparts of the body that respond to changespassing out of food that has not been digested through the anus as faecesan unborn offspring during the first eight weeks after conceptioncondition of the lungs causing breathlessness communication system that uses hormonesproteins that function as biological catalystslayers of cells at the surface of a leaflack of oxygen in water caused by excessive plant nutrientsprocess by which different kinds of organism develop from earlier onesremoval from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells including respiration) and substances in excess of requirementshard outer covering of the bodywaste products of digestiontube leading from the ovary to the uterus, through which an egg must passpart of a fat moleculeprocess by which a sperm combines with an eggan unborn offspring after the first eight weeks after conceptionroughage in the dietfibrinfibrinogenfood chainfood webfossil fuelsgall bladdergametesgastric juicegenes genetic engineering genotypesgeotropismglucagonglucoseglycogengrowthguard cellshaemoglobin haploid nucleus an insoluble protein that gets tangled up with blood cells to produce a blood clota soluble protein in blood plasmaa chart showing the flow of energy (food) from one organism to the next, beginning with a producer (e.g. mahogany tree →caterpillar → song bird → hawk)a network of interconnected food chains showing the energy flow through part of an ecosystemfuels such as coal, oil and gas formed from remains of living things that existed millions of years agobile is stored in the gall bladdermale or female germ cell (a sperm or egg)fluid that mixes with food in the stomachA length of DNA that is the unit of heredity and contains codes for a specific protein. A gene may be copied and passed on to the next generation.taking a gene from one species and putting it into another speciesgenetic makeup of an organism in terms of the alleles present (e.g. Tt or GG)a response in which a plant grows towards or away from gravityhormone that increases blood glucose concentrationa type of sugara polysaccharide, used as an energy storea permanent increase in size and dry mass, by an increase in cell number or cell size, or bothin a leaf, the guard cells change shape to open or close the stomataa protein in blood, responsible for carrying oxygena nucleus containing a single set of unpaired chromosomes (e.g. sperm and egg)herbivorehermaphroditeheterozygoushomeostasishomozygoushormoneshyphaeileum immunosuppressantdrugsincisorsingestioninheritanceinorganicinsulin intercostal musclesiriskidney tubuleskwashiorkorlactaselactic acidlactose an animal that gets its energy by eating plantshaving both male and female characteristicshaving two different alleles of a particular gene (e.g. Tt or Gg), not pure-breedingthe maintenance of a constant internal environment Having two identical alleles of a particular gene (e.g. TT or gg). Two identical homozygous individuals that breed together will be pure-breeding.a chemical substance, produced by a gland, carried by the blood, which alters the activity of one or more specific target organs and is then destroyed by the liver threads making up the main body of a funguslatter part of the small intestinesubstance taken into the body that modifies or affects chemical reactions in the bodybiting teethtaking substances (e.g. food, drink) into the body through the mouththe transmission of genetic information from generation to generationsubstances that do not derive from living thingshormone that helps reduce a high blood glucose levelmuscles between the ribscoloured part of the eye that changes shape to control amount of light entering the eyetiny tubes in the kidney that play a role in filtering the bloodcondition caused by lack of protein in the dietenzyme that breaks down lactosea waste product of anaerobic respirationa type of sugarlarge intestinelimiting factorlipaseslipidslumenlymphlymphocytesmalariamaltasemaltosemeiosis menstrual cyclemenstruationmesophyll metabolic reactionsmicropylemitosismolarsmutationmyceliummyriapodnarcoticnerve cellneurone part of the intestine where remaining water and inorganic ions pass into the bloodsomething present in the environment in such short supply that it restricts life processesenzymes that break down fatsan alternative name for fatsspace in the veins through which blood flowstissue fluid in the lymphatic capillarieswhite blood cells that kill pathogensdisease caused by a parasite carried by mosquitoes enzyme that breaks down maltosea type of sugarreduction division in which the chromosome number is halved from diploid to haploidprocess of menstruation and ovulationdischarge of blood from the lining of the uterusinner tissue of a leafchemical reactions that take place in cellssmall opening in the surface of an ovulenuclear division giving rise to genetically identical cells in which the chromosome number is maintained by the exact duplication of chromosomesgrinding teetha change in a gene or chromosomethe main body of a fungusan arthropod with many legsaddictive drugcell that carries electrical signalsalternative name for a nerve cellnicotine nitrifying bacterianitrogen-fixingbacterianucleusnutritionobesityoesophagusoestrogenoptic nerveorganorgan systemsorganicosmosisovaryoviductovulationovulesoxygen debtoxyhaemoglobin addictive drug found in tobaccobacteria that change proteins in organic material into ammonia and nitratesbacteria that change nitrogen from the air into ammoniapart of a cell that contains genetic materialtaking in of nutrients that are organic substances and mineral ions, containing raw materials or energy for growth and tissue repair, absorbing and assimilating themcondition of being severely overweighttube connecting mouth and stomachhormone that controls development of female characteristicsnerve connecting retina to braina structure made up of a group of tissues working together to perform specific functionsa group of organs with related functions, working together to perform body functionsderived from living thingsthe diffusion of water molecules from a region of their higher concentration (dilute solution) to a region of their lower concentration (concentrated solution), through a partially permeable membranethe organ in which eggs (ova) are producedtube through which an egg leaves the ovaryprocess by which an egg is released from the ovary part of the ovary of a plant; becomes the seed after fertilisationcondition after exercise during which extra oxygen is needed to break down lactic acidmolecule formed when haemoglobin combines with oxygenpalisade cellspancreas pancreatic juice partially permeablepathogenpectinasepenicillinpepsinperistalsisphagocytesphenotypephloem tubes photosynthesisphototropismplacentaplasmaplasmolysedpollinationpopulation cells near the surface of a leaf where most of the photosynthesis takes placegland containing pancreatic juicefluid containing enzymes that help digestionallowing some substances through, but not othersa harmful organismenzyme that helps to break down cell walls in fruitan antibiotica protein-digesting enzymeprocess by which muscles in the wall of the intestine cause food to be pushed alongwhite blood cells that surround and digest harmful bacteriathe physical or other features of an organism due to both its genotype and its environment (e.g. tall plant or green seed)tubes that transport sugars around a plantthe fundamental process by which plants manufacture carbohydrates from raw materials using energy from lighta response in which a plant grows towards or away from the direction from which light is comingorgan in the uterus that provides nutrients for the fetus watery constituent of blood that contains many dissolved substancescondition when the surface membrane of a plant cell is pulled away from the cell wallthe transfer of pollen grains from the male part of the plant (anther of stamen) to the female part of the plant (stigma)a group of organisms of one species, living in the same area at the same timeprimary consumer an animal that eats plantsproducersproteaseprotein pulmonary arterypulmonary veinrecessivereflex actionreflex arcreproductionrespirationretinarodsroot hair cellssecondaryconsumersense organssensitivity sexual reproduction an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesisan enzyme that breaks down proteinmolecules made up of amino acidsblood vessel from the heart to the lungsblood vessel from the lungs to the heartan allele that is only expressed when there is no dominant allele of the gene present (e.g. t or g)action that does not involve conscious thought (e.g. blinking)pathway from receptor to musclethe processes that make more of the same kind of organismthe chemical reactions that break down nutrient molecules in living cells to release energylight-sensitive part of the eyelight-sensitive cells in the retina, responsible for monochrome vision in poor lightspecialised cells that help anchor a plant and absorb water and minerals from the soilan animal that eats other animalsgroups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicalsthe ability to detect or sense changes in the environment (stimuli) and to make responsesthe process involving the fusion of haploid nuclei to form adiploid zygote and the production of genetically dissimilar offspringsickle cell anaemia small intestinesperm spongy mesophyll(layer)stomatasuspensoryligamentstendon tertiary consumertest crosstestestestosteronethoraxtissuetracheatranslocationtranspirationtrophic leveltropismsturgidurea a condition causing abnormal haemoglobin, but which appears to give protection against malariapart of the alimentary canal between the stomach and the large intestinethe male sex cellinner layer of a leaf, having air spaces between the cellsgaps in the lower epidermis of a leafstrong fibres holding the eye lens within the ciliary musclesbundle of strong, non-stretchy fibres that hold muscle to bonean animal that eats a secondary consumercrossing an unknown genotype with one showing a recessive phenotypeorgan that produces spermhormone that controls development of male secondary sexual characteristicsin humans, the chesta group of cells with similar structures, working together to perform a shared functiontube between the mouth or nose and the bronchithe movement of sucrose and amino acids in phloem evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomatathe position of an organism in a food chain, food web or pyramid of biomass, numbers or energyplant growth in response to a stimulusrigid (in plants, when they have sufficient water)an excretory substance made in the liver from excess proteins, excreted by the kidneysureterurethrauterusvacuole vascular bundlesveinsvena cavavilliwater potentialxylem vesselszygote tube carrying urine from the kidney to the bladdertube through which urine leaves the bodyorgan in which offspring grow and develop before birth liquid-filled space inside a cellstructures in a leaf that contain xylem vesselsblood vessels carrying blood to the heartthe vein carrying blood from all of the body, apart from the lungs, to the heartsmall projections on the wall of the small intestinea measure of concentration; concentrated solutions have a low water potentiala system of tubes that delivers water to parts of a planta cell resulting from the fusion of two gametes。

英文文本预处理流程English text preprocessing is a critical step in natural language processing (NLP) and text mining tasks. It involves a series of steps to clean, transform, and prepare the raw text data for further analysis and modeling. This process is essential for improving the accuracy and effectiveness of various NLP applications, such as sentiment analysis, text classification, and language generation. In this essay, we will explore the common steps involved in the English text preprocessing workflow.1. Data Acquisition:The first step in the text preprocessing workflow is to acquire the raw text data. This can be obtained from a variety of sources, such as websites, social media platforms, databases, or custom-built datasets. The data may come in different formats, such as plain text, HTML, PDF, or spreadsheets, and may require some initial processing to extract the relevant text content.2. Text Cleaning:Once the raw text data is obtained, the next step is to clean the text.This involves removing any unwanted or irrelevant information, such as HTML tags, URLs, email addresses, special characters, numbers, and punctuation marks. This step helps to remove noise and ensure that the text is in a format that can be easily processed by the subsequent steps.3. Tokenization:Tokenization is the process of breaking down the text into smaller units called tokens, which are typically individual words or phrases. This step is crucial for many NLP tasks, as it helps to identify the basic building blocks of the text. Tokenization can be done using various techniques, such as white space separation, regular expressions, or more advanced methods like sentence boundary detection.4. Stopword Removal:Stopwords are common words that do not carry much semantic meaning, such as "the," "a," "and," "is," and "to." These words are often removed from the text during the preprocessing stage, as they can introduce noise and reduce the effectiveness of subsequent analysis tasks. Stopword removal can be done using predefined lists of stopwords or by applying more advanced techniques, such as term frequency-inverse document frequency (TF-IDF) analysis.5. Lemmatization and Stemming:Lemmatization and stemming are techniques used to reduce words to their base or root form, known as the lemma or stem, respectively. Lemmatization uses a vocabulary and morphological analysis to convert words to their base forms, while stemming uses a simpler rule-based approach to remove suffixes and prefixes. These techniques help to reduce the dimensionality of the text data and improve the performance of various NLP models.6. Text Normalization:Text normalization is the process of converting the text to a consistent format, such as converting all characters to lowercase or uppercase, handling abbreviations and contractions, or standardizing the spelling of words. This step helps to ensure that the text is in a format that can be easily processed by the subsequent steps.7. Feature Extraction:Once the text has been cleaned, tokenized, and normalized, the next step is to extract relevant features from the text. This can involve techniques such as bag-of-words, n-grams, or more advanced methods like word embeddings. The choice of feature extraction technique depends on the specific NLP task and the characteristics of the text data.8. Data Augmentation:In some cases, the available text data may be limited or imbalanced,which can affect the performance of NLP models. Data augmentation is a technique used to generate additional synthetic data by applying various transformations to the existing text, such as paraphrasing, back-translation, or synonym replacement. This can help to improve the robustness and generalization of the NLP models.9. Model Training and Evaluation:The final step in the text preprocessing workflow is to train and evaluate the NLP models using the preprocessed text data. This may involve tasks such as text classification, sentiment analysis, named entity recognition, or language modeling, depending on the specific application. The performance of the models can be evaluated using various metrics, such as accuracy, precision, recall, or F1-score, and the results can be used to fine-tune the preprocessing steps or the model architecture.In conclusion, the English text preprocessing workflow is a crucial step in the NLP pipeline, as it helps to transform the raw text data into a format that can be effectively processed by various NLP models. By following the steps outlined in this essay, researchers and practitioners can improve the accuracy and performance of their NLP applications, leading to better insights and more effective decision-making.。

初中七年级英语和八年级英语作文区别全文共6篇示例，供读者参考篇1The Leap from 7th to 8th Grade English WritingEnglish class in middle school is a whirlwind of new concepts, skills, and challenges each year. As someone who just finished8th grade, I can definitely say there was a huge jump in the writing expectations between 7th and 8th grade English. While 7th grade writing focused more on basic structures and straightforward prompts, 8th grade writing ramped things up to a whole new level of complexity.In 7th grade, most of our writing assignments were pretty straightforward. We'd get prompts like "Write a narrative story about a memorable experience" or "Explain the steps of your favorite recipe" or "Persuade the reader whether pets should be allowed in school." The essays and papers we had to write stayed pretty simple and short, usually just a few paragraphs. The big focus was on making sure we understood proper paragraph structure with clear topic sentences, body details, and conclusions. We also spent a lot of time reviewing grammar skillslike subject-verb agreement, pronoun use, punctuation, and capitalization. It was all about reinforcing the fundamental building blocks of writing.In terms of techniques and strategies, 7th grade writing was more about sticking to the basics. We'd incorporate simple literary devices like similes, sensory details, and rhetorical questions to make our writing more engaging. But we didn't really dive too deep into advanced stylistic moves. The priority was just getting comfortable with expressing our thoughts in an organized, coherent way while avoiding major errors.Then we hit 8th grade English, and everything changed. Suddenly, the prompts and assignments became so much more open-ended and analytical. We'd get questions like "Analyze the character development of the protagonist across the novel" or "Compare and contrast the themes in these two short stories" or "Craft an argumentative essay evaluating whether the government should regulate social media usage."Right off the bat, we were expected to develop much more nuanced and insightful positions backed up by specific evidence from the texts. Rather than just summarizing plots, we had to interpret deeper meanings, make connections, and formulateoriginal arguments. The essays had to be longer too, usually a solid five paragraphs, with a clear, precise thesis statement.The type of writing also expanded way beyond just narratives, explanations, and opinion pieces. We started doing lots of literary analysis essays, rhetorical précis assignments, research papers, and even some creative writing like poetry and short stories. Each mode of writing came with its own set of specialized skills and conventions we had to master.It was also in 8th grade that we dove headfirst into more advanced rhetorical techniques and devices. Simple analogies and imagery weren't enough anymore. We had to start seamlessly incorporating tools like extended metaphors, allusions, parallel structure, rhetorical questions, and counterarguments into our writing. We spent so much time analyzing these devices in the works we read that we were then expected to wield them purposefully in our own pieces.Speaking of analyzing the works we read, that was another major shift between 7th and 8th grade English. Rather than just reading for entertainment or basic comprehension, we were tasked with taking a much deeper critical lens to every text. We'd get passages or whole books and have to dissect every nuance - authorial intent, historical context, literary devices, symbolism,character motivation, thematic implications, and so on. Our annotations, discussions, and writing all had to demonstrate a passionate attention to detail and ability to unpack complex ideas.I'll never forget one of our first major writing assignments in 8th grade - an analytical essay examining the use of archetypes and motifs in a Renaissance play we had read as a class. As I stared blankly at my rubric filled with terms like "thesis," "textual evidence," "commentary," and "rhetorical analysis," I felt hopelessly lost. Compared to the straightforward book reports and personal narratives of 7th grade, this was academic writing on another level!Over time though, through lots of modeling, guided practice, and targeted feedback from our teacher, my 8th grade class gradually got the hang of this new style of higher-level analysis and composition. We became more adept at formulating precise, defensible claims and substantiating them with specific examples and elaboration. We got better at anticipating and refuting counterarguments before they could even come up. Most importantly, we strengthened our ability to dig beneath the surface and discover profound insights that really made our writing sing.While there's no doubt that 8th grade writing was exponentially more rigorous than anything we faced in 7th grade, it was also so rewarding to feel my skills expanding in that way. With every essay, I gained more confidence in articulating complex thoughts, providing convincing evidence, reckoning with nuance, and speaking my truth in a powerful yet polished way. I became a more critical reader, a more persuasive writer, and overall, a deeper thinker.篇2The Leap from 7th Grade to 8th Grade English WritingEnglish class has always been one of my favorite subjects in school. I just love learning about words, reading stories, and expressing myself through writing. But I have to admit, there was a huge shift in how we approached writing assignments when I went from 7th grade to 8th grade English. It felt like the expectations just totally changed overnight!In 7th grade, our writing assignments were still pretty straightforward. We'd usually get a prompt about a personal experience or a fictional story idea. The prompts were really open-ended to let our creativity flow. For example, one assignment was to write about our most memorable summervacation. Another time we had to create a fantasy world and describe what it was like to live there. Those kinds of creative writing exercises were fun because we could let our imaginations run wild.The main focus in 7th grade was on developing a unified idea and using plenty of descriptive details to paint a picture for the reader. We had to make sure our writing flowed logically from one point to the next. But we didn't have to worry too much about providing evidence or making an argument. The expectations for 7th grade writing were more about expressing our personal thoughts, feelings and experiences in an engaging way.Our teacher would give us feedback on things like varying our sentence structure, using more vivid vocabulary, checking for spelling and grammar errors, and so on. But the content itself didn't get scrutinized too deeply. As long as we thoroughly addressed the prompt and organized our ideas into paragraphs, we were generally in good shape.Then 8th grade English hit, and man, the writing assignments got so much tougher! All of a sudden, we couldn't just freely share our opinions or creative ideas anymore. We had to learn how to construct well-developed arguments andsupport every claim with facts, quotes from text evidence, logical reasoning, and specific examples. No more "fluff" - every sentence had to directly contribute to proving our thesis statement.Instead of just personal narratives or fiction writing, we were assigned all of these analytical essays and persuasive research papers. We'd have to take real-world issues like climate change, animal rights, technology addiction - all kinds of complex topics - and craft a multi-paragraph argumentative essay around them, considering multiple perspectives.Not only did we have to develop a clear position and line of reasoning, but we were expected to address counterarguments from the other side as well. We couldn't just ignore opposing viewpoints. We had to acknowledge them and refute them with hard evidence to truly strengthen our own argument.Formatting and citation got so much more intensive too. We weren't just slapping quotes willy-nilly into our paragraphs anymore. Every time we used someone else's words or ideas, we had to carefully integrate those outside sources, citing author name, text title, date, and page number. We spent so much time learning MLA and APA formatting rules for parenthetical citations, works cited pages, properly quoting verse lines - thewhole deal. One misplaced comma on a citation could mean losing major points on an assignment!The rubrics we were graded on also got way more details. It wasn't just about completion and effort anymore. In 8th grade, our essays were picked apart based on criteria like thesis development, organizing evidence logically, making insightful analysis beyond just restating summary points, varying sentence structure and openers, sustaining a formal writing style and tone, and more. We really had to take our time self-editing and revising to ensure our essays met all the targets on those intense rubrics.It felt like a drastic transition because the early writing assignments I'd had were so open-ended and relaxed. But once we hit the higher grades, the academic expectations kicked into high gear. Suddenly, we couldn't just freely spill out our creative thoughts onto the page. We had to learn advanced composition skills like crafting sophisticated arguments, seamlessly integrating quality evidence and examples, considering multiple viewpoints, following strict formatting guidelines, polishing our tone and style - all the essential skills to set us up for writing success in high school and beyond.While those analytical and research-based writing tasks were definitely challenging, they were also incredibly valuable learning experiences. All of those essays pushed me to think more critically about complex issues, gather and evaluate sources, organize a cohesive argument, and articulate my reasoning in a clear, structured way. I know having to constantly back up my claims with solid evidence made me a much stronger writer overall.Looking back now, I can really appreciate why 8th grade ramped up the academic rigor so much when it came to writing assignments. Those analytical and argumentative essays, as difficult as they felt at the time, ended up teaching me crucial communication and critical thinking skills that have helped me tremendously, not just for future English classes, but for all of my other academic subjects too.So even though I may have missed those more open-ended creative writing assignments we used to have, I'm ultimately grateful that my 8th grade English teacher raised the bar so high. All of the practice citing sources, making evidence-based arguments, addressing counterarguments, self-editing to meet rubric criteria - it was intense, for sure, but it truly leveled up my writing abilities in invaluable ways. The shift from 7th to 8thgrade writing may have felt harsh initially, but in the end, it got me prepared to tackle high school academics and any advanced writing challenges headed my way.篇3The Big Leap from 7th to 8th Grade English WritingYo, let me tell you about the crazy difference between writing in 7th grade English and 8th grade English. It's like jumping from the kiddie pool to the deep end of the big pool!In 7th grade, the writing assignments were still pretty basic. We'd have to write simple essays and stories about stuff like our summer vacation or our favorite food. The teachers wanted us to focus on the basics - having a clear introduction, body paragraphs, and conclusion. We had to make sure our grammar and spelling were on point too.But the big emphasis was just getting us comfortable with putting our thoughts down on paper in a structured way. The topics were super straightforward and we didn't have to go too deep into analysis or anything complicated like that. As long as we covered the prompt and our writing made sense, we were golden.Now 8th grade? That's a whole different ballgame! The training wheels are OFF and it's time to take writing to another level.First off, the topics and prompts we get are way more advanced. Instead of "What I Did Last Summer", we're writing about big societal issues, analyzing pieces of literature, and really diving deep into heavier subjects. Just the other day, I had to write a persuasive essay on whether we should abolish the death penalty. Like, what? That's some heavy-duty stuff!The teachers expect us to do a lot more research too. We can't just write off the top of our heads anymore. We've got to go find credible sources, analyze different viewpoints, and then craft a well-reasoned argument incorporating evidence from our research. Talk about raising the bar!And you can forget about those super basic five-paragraph essay structures we leaned on in 7th grade. Now our essays have to be more sophisticated, with smoother transitions between ideas and more nuanced analysis woven throughout. We're expected to vary our sentence structures, use more advanced vocabulary, and generally write at a much higher level.Honestly, at first I was a little intimidated by all these new expectations in 8th grade English writing. But you know what?I've actually grown to really enjoy the challenge. Sure, it's a lot more work, but it feels good to tackle meatier topics and put more critical thinking into my writing.I feel like I'm becoming a much stronger writer and communicator overall. Instead of just regurgitating basic ideas, I'm learning how to develop well-supported arguments, organize my thoughts in a mature way, and get my point across with more clarity and sophistication.Don't get me wrong, there are definitely times when I miss those easier 7th grade writing days. But I know this more advanced writing practice is preparing me for the kind of work I'll be doing in high school and beyond. Besides, there's nothing quite like the satisfaction of turning in a killer essay that really makes a powerful point.So yeah, the jump from 7th to 8th grade writing is pretty intense. But I'm actually grateful for the chance to level up my skills in a big way. Pretty soon writing these higher-level essays will be old hat, and then I'll really be ready to blow everyone's minds in 9th grade!篇4The Big Leap from 7th to 8th Grade English CompositionsHey there, fellow students! I'm here to share my experience with the changes I faced when it came to English compositions as I transitioned from 7th to 8th grade. It was a massive shift, let me tell you!In 7th grade, English compositions felt like a walk in the park compared to what we're dealing with now in 8th grade. Back then, the topics were pretty straightforward and relatable to our daily lives. You know, stuff like "My Favorite Holiday Destination" or "The Best Birthday Gift I Ever Received." Writing about those kinds of topics was a breeze because we could simply draw from our personal experiences and express our篇5The Leap from 7th to 8th Grade English WritingWow, can you believe we're already in 8th grade? It feels like just yesterday we were those tiny 7th graders, still getting used to middle school life. But now, we're the big kids on campus! And let me tell you, that's not the only thing that's changed – our English writing has leveled up big time too!When I think back to 7th grade English, it all seems so simple now. We spent a lot of time just getting the basics down –making sure our sentences were grammatically correct, learninghow to structure a basic paragraph, and getting comfortable with different types of writing like narratives, descriptions, and simple essays.Don't get me wrong, that stuff was important! We had to master those fundamentals before we could move on to more advanced writing. But looking back, our 7th grade assignments now seem almost… well, a little bit babyish, you know?The biggest difference I've noticed in 8th grade is just how much more in-depth our writing has become. Our teachers expect us to really analyze topics from multiple angles and incorporate evidence and examples to back up our ideas. It's not just about expressing an opinion anymore – we have to critically think through complex issues.For example, in 7th grade, we might have had to write a short essay on our favorite book, describing the plot and explaining why we liked it. Pretty straightforward, right? But in 8th grade, we've been assigned essays that require us to deeply analyze themes, symbols, and character motivations in novels. We can't just say "I liked this book because it was exciting" – we have to really dig into the deeper meaning behind the story.Our vocabulary has leveled up too. I'll never forget the first few 8th grade vocabulary lists we got – they were filled with allthese crazy, multi-syllable words I had never even heard of before! Words like "ubiquitous," "eschew," and "obfuscate." At first, it felt like we were being asked to learn a whole new language on top of English! But now that we've gotten used to using more advanced vocabulary, our writing just sounds so much more sophisticated.Speaking of sounding sophisticated, we've also had to master some new writing techniques in 8th grade. Things like using transitions smoothly, incorporating quotes and evidence properly, and varying our sentence structures for better flow and rhythm. Our 7th grade selves would have been completely lost trying to implement all those skills!Another major step up is the amount of research and preparation we now have to do for essays and papers. In 7th grade, we could mostly rely on our own thoughts and experiences. But this year, we've had to spend hours in the library and online, gathering information from credible sources to use as evidence in our argumentative and analytical writing. It's a lot more work, but it's also helped us become stronger critical thinkers and writers.And let's not forget about those creative writing units – wow, have those gotten intense! I'll never forget the multi-week shortstory project we had to do last semester. We had to come up with an original plot, develop complex characters with clear motivations and arcs, incorporate symbols and motifs, and stick to the conventions of our chosen genre – whether it was fantasy, mystery, sci-fi, or something else. Our poor 7th grade selves would have been completely overwhelmed!But while the increase in difficulty and expectations for 8th grade English writing has definitely been an adjustment, I actually really enjoy the challenge now. There's something so satisfying about pouring all your effort into a piece of writing, doing deep analysis and research, and then crafting a final product that you can be really proud of. When I look back at some of my best essays and stories from this year, I can hardly believe that I was capable of producing such sophisticated, insightful writing.Who knows, maybe I'll even be a famous author or journalist someday! If I keep leveling up my writing skills at this rate, I just might have what it takes. For now though, I'll settle for feeling like one of the best writers in 8th grade. Sorry 7th graders –you've got a long way to go before you can catch up to us!篇6The Leap from 7th to 8th Grade English WritingWhew, middle school English writing sure is a journey! As I moved up from 7th to 8th grade, I realized just how much more was expected of me. While 7th grade writing focused on the basics, 8th grade raised the bar for complexity and depth. Let me walk you through some of the key differences.In 7th grade, we spent a lot of time mastering the foundations - writing clear topic sentences, using transitional words and phrases to connect ideas, and developing body paragraphs with sufficient supporting details. The essays were pretty straightforward - usually just a basic 5 paragraph structure. We'd start with an intro, have three body paragraphs, and then a conclusion wrapping it up. Simple enough, right?But then 8th grade hit, and boom! Everything got kicked up a notch. All of a sudden, our teachers expected us to elevate our analysis and argue positions in a much more sophisticated way. We had to go beyond just stating facts and develop interpretations, evaluations and judgments within our writing.Instead of those basic 5 paragraph essays, longermulti-paragraph essays became the norm. We'd have to build complex argumentative claims, acknowledging counterarguments before refuting them. Clearly organizing andbreaking down components of our theses was essential to scoring well.The types of evidence and examples required in 8th grade were also much more advanced. While personal anecdotes could carry an entire 7th grade essay, in 8th grade they were just one small piece of the puzzle. We had to integrate and analyze textual evidence from literature, credible research from academic sources, and even incorporate multimedia components like charts or images to fully explore topics.Speaking of topics, those got way more intricate and conceptual too! Where 7th grade essay prompts were pretty straightforward like "Write about your favorite book" or "Describe your cultural traditions," 8th grade challenged us with far more abstract ideas. We'd have to craft argumentative pieces taking a stance on complex societal issues, ethical dilemmas, or analyze the deeper symbolic meaning of a work of literature. No more fluff - these essays demanded higher-order critical thinking skills.Another big step up was the increased emphasis on more formal, academic writing. Sure, 7th grade touched on things like avoiding contractions and writing in third person. But 8th grade held us to a much stricter standard of precision in language,varied use of sophisticatedsyntax and mature vocabulary. You could no longer just write how you speak - there were rigorous conventions of formal style to adhere to.And of course, let's not forget about the dreaded research paper! While short research assignments started in 7th grade,8th grade was when we had our first major long-form research paper due. We had to spend weeks diligently finding and evaluating sources, taking notes, formulating and revising a thesis, organizing and substantiating multiple body sections, properly citing everything in MLA format - the works! That's when it really hit me how high the academic writing standards had climbed.Despite all those new challenges of 8th grade writing, overcoming them felt like such an accomplishment. With each essay, I gained more confidence in articulating complex ideas, substantiating claims, giving a more polished and formal voice to my perspectives. My growth as a writer prepared me to take on even more advanced assignments in high school and beyond.As daunting as it felt at first, looking back I'm grateful for how much my writing skills were sharpened in 8th grade. It stretched me out of my comfort zone and propelled me to a whole new level. The leap from 7th to 8th was huge, but alsohugely important in setting me up for future academic writing success. Bring on high school essays - I've got this!。

Dairy Glossary 乳业词汇Acid Rinse - Part of the equipment cleaning process for stainless steel and rubber parts, removes fat, protein and minerals and also reduces bacteria. (See Equipment Sanitization) 酸冲洗：专门针对设备中的不锈钢和橡胶部分的冲洗过程。

清洗油脂、蛋白质、矿物质同时也有杀菌的效果。

（参见：设备消毒）Acute - Used to describe disease where symptoms are readily evident. Treatment is generally required. 急性病Alley - A walking area for cattle within a barn such as a loafing alley, feeding alley or cross alley (walkway) from a barn to the milking parlor.小径：奶牛等动物在牛舍内活动的小径（细长型小径、喂食小径、交叉小径---从谷仓到挤奶间）Alley Scraper - A "V" shaped mechanical blade that is dragged over an alley by chain or cable to pull manure to collection channel at the end of the alley (or possibly the center of the barn). The blade then collapses and is drawn back to the opposite end of the alley. 小径刮刀（粪便用）：专门将小径内的牛粪等物质运出小径。

英语读后续写句子高中Here is an English essay on the topic "Writing Sentences after Reading in High School" with a word count of over 1000 words:Writing Sentences after Reading in High SchoolIn the realm of high school education, the skill of writing sentences after reading has become a fundamental component of language arts curricula. This practice not only enhances students' proficiency in English but also fosters critical thinking, comprehension, and the ability to articulate their understanding of the material. As students navigate the challenges of high school, mastering the art of sentence writing post-reading can equip them with invaluable tools for academic success and personal growth.The importance of reading comprehension cannot be overstated in the high school setting. Students are often tasked with analyzing a variety of literary works, from classic novels to contemporary short stories, and are expected to demonstrate their understanding through written responses. The act of writing sentences after reading serves as a bridge between the comprehension of the text and the articulation of one's thoughts and interpretations. It requiresstudents to actively engage with the material, synthesize the information, and then translate their understanding into coherent and well-structured sentences.One of the primary benefits of writing sentences after reading in high school is the development of critical thinking skills. When students are asked to compose sentences that reflect their understanding of a text, they are forced to delve deeper into the nuances of the material, identify key themes, and draw meaningful connections. This process encourages students to move beyond the surface-level understanding and to delve into the underlying meanings and implications of the reading. By engaging in this intellectual exercise, students hone their ability to analyze, interpret, and express their ideas in a clear and concise manner.Moreover, the practice of writing sentences after reading enhances students' overall proficiency in English. As they navigate the process of translating their thoughts into written form, they are required to pay close attention to grammar, syntax, and the appropriate use of vocabulary. This reinforces the students' understanding of the fundamental building blocks of the English language and helps them to develop a more sophisticated and refined writing style. Furthermore, the feedback and guidance provided by teachers on these written exercises can further refine students' language skills, ultimately improving their overall communication abilities.In addition to the academic benefits, writing sentences after reading in high school also contributes to the personal growth and development of students. The act of articulating one's understanding of a text requires a level of self-reflection and introspection that can be invaluable in the high school years. Students are encouraged to delve into their own perspectives, emotions, and interpretations, and to express them in a coherent and meaningful way. This process fosters a sense of confidence and self-awareness, as students learn to effectively communicate their ideas and engage in meaningful discussions with their peers and teachers.Furthermore, the practice of writing sentences after reading can also serve as a valuable preparation for the demands of college-level coursework. In higher education, the ability to read, comprehend, and articulate one's understanding of complex material is a crucial skill. By honing these abilities in high school, students can develop a strong foundation that will serve them well as they transition to the more rigorous academic environment of college. The confidence and competence gained through the practice of writing sentences after reading can give students a valuable edge as they navigate the challenges of tertiary education.In conclusion, the practice of writing sentences after reading in high school is a multifaceted endeavor that holds immense significancefor students' academic and personal development. By fostering critical thinking, enhancing language proficiency, and promoting self-reflection, this exercise equips students with the tools necessary to succeed not only in their high school studies, but also in their future academic and professional pursuits. As educators continue to recognize the value of this practice, it is essential that high school students embrace the opportunity to cultivate these essential skills and embark on a journey of intellectual growth and self-discovery.。

AgilentDigital Modulation in Communications Systems—An IntroductionApplication Note 1298This application note introduces the concepts of digital modulation used in many communications systems today. Emphasis is placed on explaining the tradeoffs that are made to optimize efficiencies in system design.Most communications systems fall into one of three categories: bandwidth efficient, power efficient, or cost efficient. Bandwidth efficiency describes the ability of a modulation scheme to accommodate data within a limited bandwidth. Power efficiency describes the ability of the system to reliably send information at the lowest practical power level.In most systems, there is a high priority on band-width efficiency. The parameter to be optimized depends on the demands of the particular system, as can be seen in the following two examples.For designers of digital terrestrial microwave radios, their highest priority is good bandwidth efficiency with low bit-error-rate. They have plenty of power available and are not concerned with power efficiency. They are not especially con-cerned with receiver cost or complexity because they do not have to build large numbers of them. On the other hand, designers of hand-held cellular phones put a high priority on power efficiency because these phones need to run on a battery. Cost is also a high priority because cellular phones must be low-cost to encourage more users. Accord-ingly, these systems sacrifice some bandwidth efficiency to get power and cost efficiency. Every time one of these efficiency parameters (bandwidth, power, or cost) is increased, another one decreases, becomes more complex, or does not perform well in a poor environment. Cost is a dom-inant system priority. Low-cost radios will always be in demand. In the past, it was possible to make a radio low-cost by sacrificing power and band-width efficiency. This is no longer possible. The radio spectrum is very valuable and operators who do not use the spectrum efficiently could lose their existing licenses or lose out in the competition for new ones. These are the tradeoffs that must be considered in digital RF communications design. This application note covers•the reasons for the move to digital modulation;•how information is modulated onto in-phase (I) and quadrature (Q) signals;•different types of digital modulation;•filtering techniques to conserve bandwidth; •ways of looking at digitally modulated signals;•multiplexing techniques used to share the transmission channel;•how a digital transmitter and receiver work;•measurements on digital RF communications systems;•an overview table with key specifications for the major digital communications systems; and •a glossary of terms used in digital RF communi-cations.These concepts form the building blocks of any communications system. If you understand the building blocks, then you will be able to under-stand how any communications system, present or future, works.Introduction25 5 677 7 8 8 9 10 10 1112 12 12 13 14 14 15 15 16 17 18 19 20 21 22 22 23 23 24 25 26 27 28 29 29 30 311. Why Digital Modulation?1.1 Trading off simplicity and bandwidth1.2 Industry trends2. Using I/Q Modulation (Amplitude and Phase Control) to Convey Information2.1 Transmitting information2.2 Signal characteristics that can be modified2.3 Polar display—magnitude and phase representedtogether2.4 Signal changes or modifications in polar form2.5 I/Q formats2.6 I and Q in a radio transmitter2.7 I and Q in a radio receiver2.8 Why use I and Q?3. Digital Modulation Types and Relative Efficiencies3.1 Applications3.1.1 Bit rate and symbol rate3.1.2 Spectrum (bandwidth) requirements3.1.3 Symbol clock3.2 Phase Shift Keying (PSK)3.3 Frequency Shift Keying3.4 Minimum Shift Keying (MSK)3.5 Quadrature Amplitude Modulation (QAM)3.6 Theoretical bandwidth efficiency limits3.7 Spectral efficiency examples in practical radios3.8 I/Q offset modulation3.9 Differential modulation3.10 Constant amplitude modulation4. Filtering4.1 Nyquist or raised cosine filter4.2 Transmitter-receiver matched filters4.3 Gaussian filter4.4 Filter bandwidth parameter alpha4.5 Filter bandwidth effects4.6 Chebyshev equiripple FIR (finite impulse response) filter4.7 Spectral efficiency versus power consumption5. Different Ways of Looking at a Digitally Modulated Signal Time and Frequency Domain View5.1 Power and frequency view5.2 Constellation diagrams5.3 Eye diagrams5.4 Trellis diagramsTable of Contents332 32 32 33 33 34 3435 35 3637 37 37 38 38 39 39 39 40 41 41 42 434344466. Sharing the Channel6.1 Multiplexing—frequency6.2 Multiplexing—time6.3 Multiplexing—code6.4 Multiplexing—geography6.5 Combining multiplexing modes6.6 Penetration versus efficiency7. How Digital Transmitters and Receivers Work7.1 A digital communications transmitter7.2 A digital communications receiver8. Measurements on Digital RF Communications Systems 8.1 Power measurements8.1.1 Adjacent Channel Power8.2 Frequency measurements8.2.1 Occupied bandwidth8.3 Timing measurements8.4 Modulation accuracy8.5 Understanding Error Vector Magnitude (EVM)8.6 Troubleshooting with error vector measurements8.7 Magnitude versus phase error8.8 I/Q phase error versus time8.9 Error Vector Magnitude versus time8.10 Error spectrum (EVM versus frequency)9. Summary10. Overview of Communications Systems11. Glossary of TermsTable of Contents (continued)4The move to digital modulation provides more information capacity, compatibility with digital data services, higher data security, better quality communications, and quicker system availability. Developers of communications systems face these constraints:•available bandwidth•permissible power•inherent noise level of the systemThe RF spectrum must be shared, yet every day there are more users for that spectrum as demand for communications services increases. Digital modulation schemes have greater capacity to con-vey large amounts of information than analog mod-ulation schemes. 1.1 Trading off simplicity and bandwidthThere is a fundamental tradeoff in communication systems. Simple hardware can be used in transmit-ters and receivers to communicate information. However, this uses a lot of spectrum which limits the number of users. Alternatively, more complex transmitters and receivers can be used to transmit the same information over less bandwidth. The transition to more and more spectrally efficient transmission techniques requires more and more complex hardware. Complex hardware is difficult to design, test, and build. This tradeoff exists whether communication is over air or wire, analog or digital.Figure 1. The Fundamental Tradeoff1. Why Digital Modulation?51.2 Industry trendsOver the past few years a major transition has occurred from simple analog Amplitude Mod-ulation (AM) and Frequency/Phase Modulation (FM/PM) to new digital modulation techniques. Examples of digital modulation include•QPSK (Quadrature Phase Shift Keying)•FSK (Frequency Shift Keying)•MSK (Minimum Shift Keying)•QAM (Quadrature Amplitude Modulation) Another layer of complexity in many new systems is multiplexing. Two principal types of multiplex-ing (or “multiple access”) are TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access). These are two different ways to add diversity to signals allowing different signals to be separated from one another.Figure 2. Trends in the Industry62.1 Transmitting informationTo transmit a signal over the air, there are three main steps:1.A pure carrier is generated at the transmitter.2.The carrier is modulated with the informationto be transmitted. Any reliably detectablechange in signal characteristics can carryinformation.3.At the receiver the signal modifications orchanges are detected and demodulated.2.2 Signal characteristics that can be modified There are only three characteristics of a signal that can be changed over time: amplitude, phase, or fre-quency. However, phase and frequency are just dif-ferent ways to view or measure the same signal change. In AM, the amplitude of a high-frequency carrier signal is varied in proportion to the instantaneous amplitude of the modulating message signal.Frequency Modulation (FM) is the most popular analog modulation technique used in mobile com-munications systems. In FM, the amplitude of the modulating carrier is kept constant while its fre-quency is varied by the modulating message signal.Amplitude and phase can be modulated simultane-ously and separately, but this is difficult to gener-ate, and especially difficult to detect. Instead, in practical systems the signal is separated into another set of independent components: I(In-phase) and Q(Quadrature). These components are orthogonal and do not interfere with each other.Figure 3. Transmitting Information (Analog or Digital)Figure 4. Signal Characteristics to Modify2. Using I/Q Modulation to Convey Information72.3 Polar display—magnitude and phase repre-sented togetherA simple way to view amplitude and phase is with the polar diagram. The carrier becomes a frequency and phase reference and the signal is interpreted relative to the carrier. The signal can be expressed in polar form as a magnitude and a phase. The phase is relative to a reference signal, the carrier in most communication systems. The magnitude is either an absolute or relative value. Both are used in digital communication systems. Polar diagrams are the basis of many displays used in digital com-munications, although it is common to describe the signal vector by its rectangular coordinates of I (In-phase) and Q(Quadrature).2.4 Signal changes or modifications inpolar formFigure 6 shows different forms of modulation in polar form. Magnitude is represented as the dis-tance from the center and phase is represented as the angle.Amplitude modulation (AM) changes only the magnitude of the signal. Phase modulation (PM) changes only the phase of the signal. Amplitude and phase modulation can be used together. Frequency modulation (FM) looks similar to phase modulation, though frequency is the controlled parameter, rather than relative phase.Figure 6. Signal Changes or Modifications8One example of the difficulties in RF design can be illustrated with simple amplitude modulation. Generating AM with no associated angular modula-tion should result in a straight line on a polar display. This line should run from the origin to some peak radius or amplitude value. In practice, however, the line is not straight. The amplitude modulation itself often can cause a small amount of unwanted phase modulation. The result is a curved line. It could also be a loop if there is any hysteresis in the system transfer function. Some amount of this distortion is inevitable in any sys-tem where modulation causes amplitude changes. Therefore, the degree of effective amplitude modu-lation in a system will affect some distortion parameters.2.5 I/Q formatsIn digital communications, modulation is often expressed in terms of I and Q. This is a rectangular representation of the polar diagram. On a polar diagram, the I axis lies on the zero degree phase reference, and the Q axis is rotated by 90 degrees. The signal vector’s projection onto the I axis is its “I” component and the projection onto the Q axisis its “Q” component.Figure 7. “I-Q” Format92.6 I and Q in a radio transmitterI/Q diagrams are particularly useful because they mirror the way most digital communications sig-nals are created using an I/Q modulator. In the transmitter, I and Q signals are mixed with the same local oscillator (LO). A 90 degree phase shifter is placed in one of the LO paths. Signals that are separated by 90 degrees are also known as being orthogonal to each other or in quadrature. Signals that are in quadrature do not interfere with each other. They are two independent compo-nents of the signal. When recombined, they are summed to a composite output signal. There are two independent signals in I and Q that can be sent and received with simple circuits. This simpli-fies the design of digital radios. The main advan-tage of I/Q modulation is the symmetric ease of combining independent signal components into a single composite signal and later splitting such a composite signal into its independent component parts. 2.7 I and Q in a radio receiverThe composite signal with magnitude and phase (or I and Q) information arrives at the receiver input. The input signal is mixed with the local oscillator signal at the carrier frequency in two forms. One is at an arbitrary zero phase. The other has a 90 degree phase shift. The composite input signal (in terms of magnitude and phase) is thus broken into an in-phase, I, and a quadrature, Q, component. These two components of the signal are independent and orthogonal. One can be changed without affecting the other. Normally, information cannot be plotted in a polar format and reinterpreted as rectangular values without doing a polar-to-rectangular conversion. This con-version is exactly what is done by the in-phase and quadrature mixing processes in a digital radio. A local oscillator, phase shifter, and two mixers can perform the conversion accurately and efficiently.Figure 8. I and Q in a Practical Radio Transmitter Figure 9. I and Q in a Radio Receiver102.8 Why use I and Q?Digital modulation is easy to accomplish with I/Q modulators. Most digital modulation maps the data to a number of discrete points on the I/Q plane. These are known as constellation points. As the sig-nal moves from one point to another, simultaneous amplitude and phase modulation usually results. To accomplish this with an amplitude modulator and a phase modulator is difficult and complex. It is also impossible with a conventional phase modu-lator. The signal may, in principle, circle the origin in one direction forever, necessitating infinite phase shifting capability. Alternatively, simultaneous AM and Phase Modulation is easy with an I/Q modulator. The I and Q control signals are bounded, but infi-nite phase wrap is possible by properly phasing the I and Q signals.This section covers the main digital modulation formats, their main applications, relative spectral efficiencies, and some variations of the main modulation types as used in practical systems. Fortunately, there are a limited number of modula-tion types which form the building blocks of any system.3.1 ApplicationsThe table below covers the applications for differ-ent modulation formats in both wireless communi-cations and video. Although this note focuses on wireless communica-tions, video applications have also been included in the table for completeness and because of their similarity to other wireless communications.3.1.1 Bit rate and symbol rateTo understand and compare different modulation format efficiencies, it is important to first under-stand the difference between bit rate and symbol rate. The signal bandwidth for the communications channel needed depends on the symbol rate, not on the bit rate.Symbol rate =bit ratethe number of bits transmitted with each symbol 3. Digital Modulation Types and Relative EfficienciesBit rate is the frequency of a system bit stream. Take, for example, a radio with an 8 bit sampler, sampling at 10 kHz for voice. The bit rate, the basic bit stream rate in the radio, would be eight bits multiplied by 10K samples per second, or 80 Kbits per second. (For the moment we will ignore the extra bits required for synchronization, error correction, etc.)Figure 10 is an example of a state diagram of a Quadrature Phase Shift Keying (QPSK) signal. The states can be mapped to zeros and ones. This is a common mapping, but it is not the only one. Any mapping can be used.The symbol rate is the bit rate divided by the num-ber of bits that can be transmitted with each sym-bol. If one bit is transmitted per symbol, as with BPSK, then the symbol rate would be the same as the bit rate of 80 Kbits per second. If two bits are transmitted per symbol, as in QPSK, then the sym-bol rate would be half of the bit rate or 40 Kbits per second. Symbol rate is sometimes called baud rate. Note that baud rate is not the same as bit rate. These terms are often confused. If more bits can be sent with each symbol, then the same amount of data can be sent in a narrower spec-trum. This is why modulation formats that are more complex and use a higher number of states can send the same information over a narrower piece of the RF spectrum.3.1.2 Spectrum (bandwidth) requirementsAn example of how symbol rate influences spec-trum requirements can be seen in eight-state Phase Shift Keying (8PSK). It is a variation of PSK. There are eight possible states that the signal can transi-tion to at any time. The phase of the signal can take any of eight values at any symbol time. Since 23= 8, there are three bits per symbol. This means the symbol rate is one third of the bit rate. This is relatively easy to decode.Figure 10. Bit Rate and Symbol Rate Figure 11. Spectrum Requirements3.1.3 Symbol ClockThe symbol clock represents the frequency and exact timing of the transmission of the individual symbols. At the symbol clock transitions, the trans-mitted carrier is at the correct I/Q(or magnitude/ phase) value to represent a specific symbol (a specific point in the constellation).3.2 Phase Shift KeyingOne of the simplest forms of digital modulation is binary or Bi-Phase Shift Keying (BPSK). One appli-cation where this is used is for deep space teleme-try. The phase of a constant amplitude carrier sig-nal moves between zero and 180 degrees. On an I and Q diagram, the I state has two different values. There are two possible locations in the state dia-gram, so a binary one or zero can be sent. The symbol rate is one bit per symbol.A more common type of phase modulation is Quadrature Phase Shift Keying (QPSK). It is used extensively in applications including CDMA (Code Division Multiple Access) cellular service, wireless local loop, Iridium (a voice/data satellite system) and DVB-S (Digital Video Broadcasting — Satellite). Quadrature means that the signal shifts between phase states which are separated by 90 degrees. The signal shifts in increments of 90 degrees from 45 to 135, –45, or –135 degrees. These points are chosen as they can be easily implemented using an I/Q modulator. Only two I values and two Q values are needed and this gives two bits per symbol. There are four states because 22= 4. It is therefore a more bandwidth-efficient type of modulation than BPSK, potentially twice as efficient.Figure 12. Phase Shift Keying3.3 Frequency Shift KeyingFrequency modulation and phase modulation are closely related. A static frequency shift of +1 Hz means that the phase is constantly advancing at the rate of 360 degrees per second (2 πrad/sec), relative to the phase of the unshifted signal.FSK (Frequency Shift Keying) is used in many applications including cordless and paging sys-tems. Some of the cordless systems include DECT (Digital Enhanced Cordless Telephone) and CT2 (Cordless Telephone 2).In FSK, the frequency of the carrier is changed as a function of the modulating signal (data) being transmitted. Amplitude remains unchanged. In binary FSK (BFSK or 2FSK), a “1” is represented by one frequency and a “0” is represented by another frequency.3.4 Minimum Shift KeyingSince a frequency shift produces an advancing or retarding phase, frequency shifts can be detected by sampling phase at each symbol period. Phase shifts of (2N + 1) π/2radians are easily detected with an I/Q demodulator. At even numbered sym-bols, the polarity of the I channel conveys the transmitted data, while at odd numbered symbols the polarity of the Q channel conveys the data. This orthogonality between I and Q simplifies detection algorithms and hence reduces power con-sumption in a mobile receiver. The minimum fre-quency shift which yields orthogonality of I and Q is that which results in a phase shift of ±π/2radi-ans per symbol (90 degrees per symbol). FSK with this deviation is called MSK (Minimum Shift Keying). The deviation must be accurate in order to generate repeatable 90 degree phase shifts. MSK is used in the GSM (Global System for Mobile Communications) cellular standard. A phase shift of +90 degrees represents a data bit equal to “1,”while –90 degrees represents a “0.” The peak-to-peak frequency shift of an MSK signal is equal to one-half of the bit rate.FSK and MSK produce constant envelope carrier signals, which have no amplitude variations. This is a desirable characteristic for improving the power efficiency of transmitters. Amplitude varia-tions can exercise nonlinearities in an amplifier’s amplitude-transfer function, generating spectral regrowth, a component of adjacent channel power. Therefore, more efficient amplifiers (which tend to be less linear) can be used with constant-envelope signals, reducing power consumption.Figure 13. Frequency Shift KeyingMSK has a narrower spectrum than wider devia-tion forms of FSK. The width of the spectrum is also influenced by the waveforms causing the fre-quency shift. If those waveforms have fast transi-tions or a high slew rate, then the spectrumof the transmitter will be broad. In practice, the waveforms are filtered with a Gaussian filter, resulting in a narrow spectrum. In addition, the Gaussian filter has no time-domain overshoot, which would broaden the spectrum by increasing the peak deviation. MSK with a Gaussian filter is termed GMSK (Gaussian MSK).3.5 Quadrature Amplitude ModulationAnother member of the digital modulation family is Quadrature Amplitude Modulation (QAM). QAM is used in applications including microwave digital radio, DVB-C (Digital Video Broadcasting—Cable), and modems.In 16-state Quadrature Amplitude Modulation (16QAM), there are four I values and four Q values. This results in a total of 16 possible states for the signal. It can transition from any state to any other state at every symbol time. Since 16 = 24, four bits per symbol can be sent. This consists of two bits for I and two bits for Q. The symbol rate is one fourth of the bit rate. So this modulation format produces a more spectrally efficient transmission. It is more efficient than BPSK, QPSK, or 8PSK. Note that QPSK is the same as 4QAM.Another variation is 32QAM. In this case there are six I values and six Q values resulting in a total of 36 possible states (6x6=36). This is too many states for a power of two (the closest power of two is 32). So the four corner symbol states, which take the most power to transmit, are omitted. This reduces the amount of peak power the transmitter has to generate. Since 25= 32, there are five bits per sym-bol and the symbol rate is one fifth of the bit rate. The current practical limits are approximately256QAM, though work is underway to extend the limits to 512 or 1024 QAM. A 256QAM system uses 16 I-values and 16 Q-values, giving 256 possible states. Since 28= 256, each symbol can represent eight bits. A 256QAM signal that can send eight bits per symbol is very spectrally efficient. However, the symbols are very close together and are thus more subject to errors due to noise and distortion. Such a signal may have to be transmit-ted with extra power (to effectively spread the symbols out more) and this reduces power efficiency as compared to simpler schemes.Figure 14. Quadrature Amplitude ModulationCompare the bandwidth efficiency when using256QAM versus BPSK modulation in the radio example in section 3.1.1 (which uses an eight-bit sampler sampling at 10 kHz for voice). BPSK uses80 Ksymbols-per-second sending 1 bit per symbol.A system using 256QAM sends eight bits per sym-bol so the symbol rate would be 10 Ksymbols per second. A 256QAM system enables the same amount of information to be sent as BPSK using only one eighth of the bandwidth. It is eight times more bandwidth efficient. However, there is a tradeoff. The radio becomes more complex and is more susceptible to errors caused by noise and dis-tortion. Error rates of higher-order QAM systems such as this degrade more rapidly than QPSK as noise or interference is introduced. A measureof this degradation would be a higher Bit Error Rate (BER).In any digital modulation system, if the input sig-nal is distorted or severely attenuated the receiver will eventually lose symbol lock completely. If the receiver can no longer recover the symbol clock, it cannot demodulate the signal or recover any infor-mation. With less degradation, the symbol clock can be recovered, but it is noisy, and the symbol locations themselves are noisy. In some cases, a symbol will fall far enough away from its intended position that it will cross over to an adjacent posi-tion. The I and Q level detectors used in the demodulator would misinterpret such a symbol as being in the wrong location, causing bit errors. QPSK is not as efficient, but the states are much farther apart and the system can tolerate a lot more noise before suffering symbol errors. QPSK has no intermediate states between the four corner-symbol locations, so there is less opportunity for the demodulator to misinterpret symbols. QPSK requires less transmitter power than QAM to achieve the same bit error rate.3.6 Theoretical bandwidth efficiency limits Bandwidth efficiency describes how efficiently the allocated bandwidth is utilized or the ability of a modulation scheme to accommodate data, within a limited bandwidth. The table below shows the theoretical bandwidth efficiency limits for the main modulation types. Note that these figures cannot actually be achieved in practical radios since they require perfect modulators, demodula-tors, filter, and transmission paths.If the radio had a perfect (rectangular in the fre-quency domain) filter, then the occupied band-width could be made equal to the symbol rate.Techniques for maximizing spectral efficiency include the following:•Relate the data rate to the frequency shift (as in GSM).•Use premodulation filtering to reduce the occupied bandwidth. Raised cosine filters,as used in NADC, PDC, and PHS, give thebest spectral efficiency.•Restrict the types of transitions.Modulation Theoretical bandwidthformat efficiencylimitsMSK 1bit/second/HzBPSK 1bit/second/HzQPSK 2bits/second/Hz8PSK 3bits/second/Hz16 QAM 4 bits/second/Hz32 QAM 5 bits/second/Hz64 QAM 6 bits/second/Hz256 QAM 8 bits/second/HzEffects of going through the originTake, for example, a QPSK signal where the normalized value changes from 1, 1 to –1, –1. When changing simulta-neously from I and Q values of +1 to I and Q values of –1, the signal trajectory goes through the origin (the I/Q value of 0,0). The origin represents 0 carrier magnitude. A value of 0 magnitude indicates that the carrier amplitude is 0 for a moment.Not all transitions in QPSK result in a trajectory that goes through the origin. If I changes value but Q does not (or vice-versa) the carrier amplitude changes a little, but it does not go through zero. Therefore some symbol transi-tions will result in a small amplitude variation, while others will result in a very large amplitude variation. The clock-recovery circuit in the receiver must deal with this ampli-tude variation uncertainty if it uses amplitude variations to align the receiver clock with the transmitter clock. Spectral regrowth does not automatically result from these trajectories that pass through or near the origin. If the amplifier and associated circuits are perfectly linear, the spectrum (spectral occupancy or occupied bandwidth) will be unchanged. The problem lies in nonlinearities in the circuits.A signal which changes amplitude over a very large range will exercise these nonlinearities to the fullest extent. These nonlinearities will cause distortion products. In con-tinuously modulated systems they will cause “spectral regrowth” or wider modulation sidebands (a phenomenon related to intermodulation distortion). Another term which is sometimes used in this context is “spectral splatter.”However this is a term that is more correctly used in asso-ciation with the increase in the bandwidth of a signal caused by pulsing on and off.3.7 Spectral efficiency examples inpractical radiosThe following examples indicate spectral efficien-cies that are achieved in some practical radio systems.The TDMA version of the North American Digital Cellular (NADC) system, achieves a 48 Kbits-per-second data rate over a 30 kHz bandwidth or 1.6 bits per second per Hz. It is a π/4 DQPSK based system and transmits two bits per symbol. The theoretical efficiency would be two bits per second per Hz and in practice it is 1.6 bits per second per Hz.Another example is a microwave digital radio using 16QAM. This kind of signal is more susceptible to noise and distortion than something simpler such as QPSK. This type of signal is usually sent over a direct line-of-sight microwave link or over a wire where there is very little noise and interference. In this microwave-digital-radio example the bit rate is 140 Mbits per second over a very wide bandwidth of 52.5 MHz. The spectral efficiency is 2.7 bits per second per Hz. To implement this, it takes a very clear line-of-sight transmission path and a precise and optimized high-power transceiver.。

MODULE 1Concepts and terminology for describing language描述语言的术语及概念GRAMMAR语法Active voice主动语态passive voice.被动语态Adjective形容词comparative adjective形容词比较级demonstrative adjective指代形容词possessive adjective所有格形容词（代词所有格）Asuperlative adjective形容词最高级Adverb副词Auxiliary verb:助动词Article冠词An article can be definite (the), indefinite (a) or zero (-), e.g.I was at (-) home in the sitting room when Iheard a noise.AspectA way of looking atverbforms not purely in relation to time. The perfect, continuous and simple areaspects. The continuous aspect, for example, suggests that something is happening temporarily.Base form of the verb:动词基本形式Clause从句A clause consists of a verb and (generally) a subject. A clause can be a full sentence or a part of asentence.Main clause主句When the teacher arrived,the students stopped talking.Subordinate clause从句When the teacher arrived,the students stopped talking.Relative clause定语从句The students who were sitting near the front stood up._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 20052Collective noun:集合名词Compound noun:复合名词Conditional条件句First conditional,第一条件句Second conditional,第二条件句Third conditional.第三条件句Conjunction连词A conjunction (or connector) is used to connect words, phrases, clauses or sentences, e.g.I like tea butI don’t like coffee because it’s too strong for me.Connector:连词Countable noun:可数名词Demonstrative adjective:指示形容词.Demonstrative pronoun:指示代词.Dependent preposition:非独立介词Determiner限定词A determiner is used to make clear which noun is referred to, or to give information about quantity, andincludes words such asthe,a,this,that,my,some,e.g.That car is mine.Direct speech直接引语The actual words someone says, e.g.He said, ‘My name is Ron.’First conditional:seeconditional forms.Gerund,-ing form动名词形式A noun which is made from the present participle form of a verb, e.g.I hate shopping.Grammatical structure语法结构The arrangement of words into meaningful sentences. A grammatical structure is also a grammaticallanguage item, e.g. present perfect simple.Imperative祈使句The form of averbthat gives an order or instruction, e.g.Turn to page 10.Indirect questionThe words someone uses when they are telling someone what somebody else asked, e.g.Peter askedSue what she meant.An indirect question can also be used when someone wants to ask something in a more polite way, e.g.‘I was wondering if you could help me’ (indirect questi on) instead of ‘Could you help me?’ (directquestion).Seedirect question.Indirect speech:seereported statement.间接引语Infinitive:seeverb.不定式Infinitive of purpose表示目的的不定式This is used to express why something is done, e.g.I went to the lesson to learn English.-ing/-ed adjective:seeadjective.形容词加ing或ed形式Intensifier加强语气的词汇A word used to make the meaning of another word stronger, e.g.He’s much taller than his brother;I’mvery tired.Interrogative疑问句A question form.Irregular verb:seeverb.不规则动词Main clause:seeclause.主句Modal verb:seeverb.情态动词Noun名词A person, place or thing, e.g.elephant,girl,grass,school.Acollective nounis a noun which includes a group of people or things, e.g.the police,the government.集合名词Acompound nounis a combination of two or more words which are used as a single word, e.g.aflower复合名词shop,a headache.Acountablenoun has a singular and plural form, e.g.book books.可数名词Anuncountablenoun does not have a plural form, rmation.不可数名词Aproper nounis the name of a person or place, e.g.Robert,London.专有名词Asingular nounis one person, place or thing.单数名词Aplural nounis more than one person, place or thing and can be regular or irregular, e.g.boys,women.复数名词Object宾语This is a noun or phrase that describes the thing or person that is affected by the action of a verb, e.g.Isaw Mary in the classroom.Seesubject.Participle (past and present)现在分词及过去分词The form of the verb that is used to make tenses or adjectives, e.g.an interesting film(presentparticiple);I haven’t seen him today. (past participle)Passive voice被动语态In apassivesentence, something is done to or happens to the subject of the verb, e.g. The tree was hitby the car.Seeactive voice.Past perfect simple and continuous,progressive:seetense.过去完成时及进行时Past simple and past continuous,progressive:seetense.大凡过去时及进行式Personal pronoun:seepronoun.人称代词Phrase短语Possessive ‘s’ and whose所有格‘sWays of showing or asking who something belongs to, e.g. ‘Whose book is it?’ ‘It’s Sue’s’.Preposition介词A word used before a noun, noun phrase or pronoun to connect it to another word, e.g.He was in thegarden.Adependent prepositionis a word that is always used with a particular noun, verb or adjective, e.g.interested in,depend on,bored with.Present continuous,progressive for future:seetense.现在进行时Present perfect simple and continuous,progressive:seetense.现在完成时及进行时Present simple and continuous,progressive:seetense.大凡现在时及进行时Pronoun代词A word that replaces or refers to a noun or noun phrase just mentioned.Demonstrative pronoun, e.g.this,that.指示代词Object pronoun, e.g.him.代词宾格Personal pronoun, e.g.I(subject pronoun),me(object pronoun)人称代词Possessive pronoun, e.g.mine名词性代词Reflexive pronoun, e.g.myself反身代词Relative pronoun, e.g.which关系代词Proper noun:seenoun.Punctuation标点符号The symbols or marks used to organise writing intoclauses,phrasesand sentences to make themeaning clear, e.g. full stop, capital letter, apostrophe and comma.Quantifier量词A word or phrase such as ‘much’, ‘few’ or ‘a lot of’ which is used with a noun to showan amount, e.g.Idon’t have much time; I have a lot of books.Question tag问号A phrase such as ‘isn’t it?’ or ‘doesn’t he?’ that is added to the end of a sentence to make it a question,or to check that someone agrees with the statement, e.g.It’s very cold,isn’t it?Reflexive pronoun:seepronoun.Regular verb:seeverb.规则动词Relative clause:seeclause.定语从句Relative pronoun:seepronoun.关系代词Reported statement间接引语When someone’s words are reported by another person, e.g.She said she was sorry. Seeindirectquestion.Reporting verb间接引语中使用的动词A verb such as ‘tell’, ‘advise’, ‘suggest’ used inindirect speechto report what someone has said, e.g.Jane advised John to study harder.Second conditional:seeconditional forms.Singular noun:seenoun.Subject主语This is the noun or phrase that goes before the verb in a sentence to show who is doing the action, e.g.John plays tennis every Saturday. Seeobject._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 20055Subject-verb agreement主谓一致When the form of the verb matches the person doing the action of the verb, e.g.I walk,he walks. If astudent writesIwalks, then it is wrong because there is no subject-verb agreement.Subordinate clause:seeclause.从句Superlative adjective:seeadjective.形容此最高级Tense时态A form of the verb that shows whether something happens in the past, present or future, e.g.Past perfect simple and continuous,progressive过去完成时及进行时After I had phoned Mary, I went out. (past perfect simple)I had been studying for three hours, so I felt quite tired. (past perfect continuous, progressive)Past simple and past continuous,progressive大凡过去时及进行时I was talking(past continuous, progressive)to my friend when the taxi came. (past simple)Present continuous,progressive for future进行时表将来What are you doing at the weekend?Present perfect simple and continuous,progressive现在完成时及进行时I have known him for a long time(present perfect simple).I have been studying for three years(present perfect continuous, progressive).Present simple and continuous,progressive大凡现在时及进行时I work at a school(present simple) andI am working in London now(present continuous, progressive).Third conditional:seeconditional forms.Third person第三人称Averbor apronounwhich shows that somebody or something is being spoken about, e.g. He, she, it,they.Time expression时间表达式A word or phrase that indicates a time period, such asafter,by, e.g.I will meet you after the lesson.Uncountable noun:seenoun.Used to过去常常做某事A structure that shows something happened in the past but does not happen now, e.g.I used to live inLondon,but now I live in Paris.Verb动词The word which follows the subject of a sentence, and is sometimes described as the ‘action’ word, e.g.I like cheese;He speaks Italian.Anauxiliary verbis a verb used with other verbs to make questions, negatives and tenses, e.g.be,do,have.助动词Thebase form of the verbis the infinitive form of a verb without ‘to’, e.g.go.动词的基本形式Theinfinitiveform is thebase form of a verbwith ‘to’. It is used after another verb, after an adjectiveor noun or as the subject or object of a sentence, e.g. “I want to study’, ‘It’s difficult to understand’.动词不定式Anirregular verbdoes not follow the same rule as regular verbs. Each irregular verb has its own wayof forming the past simple and past participle, e.g.go went(past simple) gone(past participle).不规则动词Amodal verbis a verb used with other verbs to show ideas such as ability or obligation or possibility.Theyincludecan,must,will,should, e.g.I can speak French, but I should study even harder.情态动词Aregular verbchanges its forms by adding-edin the past simple and past participle, e.g.walk walked规则动词(past simple).Verb pattern动词搭配The form of the words following the verb, e.g.he advised me to get there early. (advise+ objectpronoun +to+baseform)_________________________________________________________________ _____________________________© UCLES Cambridge ESOL 20056LEXIS词汇Affix词缀A meaningful group of letters added to the beginning or end of a word to make a new word.Affixationis the process of adding aprefixorsuffixto word.Aprefixis a meaningful group of letters added to the beginning of a word,e.g.appear–disappear.前缀Asuffixis a meaningful group of letters added to the end of a word to make a new word which can be adifferent part of speech, e.g.care–careful.后缀Antonym反义词The opposite of another word, e.g.hotis the antonym ofcold.Collocation搭配Words which are used together regularly, e.g.The teacher made a presentationNOTThe teacherperformed a presentation.Compounds合成词Nouns, verbs, adjectives or prepositions that are made up of two or more words, e.g.assistant officemanager,bring back,long-legged,due to.False friend简易误认的词汇A word in the target language which looks or sounds as if it has the same meaning as a similar word inthelearners’first language but does not.Homophone同音词A word which sounds the same as another word, but has a different meaning or spelling, e.g.I knew hehad won;I bought a new book.Idiom习语A group of words that are used together, in which the meaning of the whole word group is different fromthe meaning of each individual word, e.g.She felt under the weathermeans thatshe felt ill.Lexical set词群A group of words or phrases that are about the same topic, e.g.weather–storm,to rain,wind,cloudyetc.LexisIndividual words or sets of words, e.g.homework,study,whiteboard,get dressed,be on time.Multi-word verb:seephrasal verb.Part(s) of speechA description of the function of a word or a phrase in a sentence,e.g.noun,verb,adjective.Phrasal verb,multi-word verb短语动词及由多个词构成的动词短语A verb which is made up of more than one word (e.g. averb+adverbparticle orpreposition) whichhas a different meaning from each individual word, e.g.look after–A mother looks after her children.Prefix:seeaffix.前缀Suffix:seeaffix.后缀SynonymA word which has the same or nearly the same meaning as another word,e.g.niceis a synonym ofpleasant.PHONOLOGY语音Spoken language in which the words join to form a connected stream of sounds.Consonant辅音Any letter of the English alphabet except the vowelsa,e,i,o uand sometimesy. Seevowel._____________________________________________________________ _________________________________© UCLES Cambridge ESOL 20057Contraction缩写A shorter form of a word or words, e.g.you have=you’ve;it is=it’s.Diphthong双元音A vowel combination usually involving a quick but smooth movement from one vowel to another, e.g./a/as inmy.Feature (e.g. of connected speech)特征A feature of something is an interesting or important part or characteristic of it.Intonation语调The way the level of a speaker’s voice changes, often to show how they feel about something, e.g. ifthey are angry or pleased. Intonation can be rising or falling or both.Linking连读The way different sounds can link into each other in connected speech, e.g.it’s a good day–/ ts ʌde /Main stress:seestress.主重音Minimal pairTwo words which are different from each other only by one meaningful sound, and by their meaning,e.g.hear,fear.Phoneme音位The smallest sound unit which can make a difference to meaning e.g. /p/ inpan, /b/ inban. Phonemeshave their own symbols (phonemic symbols), each of which represents one sound. Words can bepresented inphonemic script音位标记(usually International Phonetic Alphabet or IPA), e.g. /d kt /–doctor.Phonemic transcriptionisused in dictionaries to aid pronunciation.Rhyme押韵1. Words that sound the same, e.g.hat,cat.2. A song or poem with words that sound the same at the end of each lineI believe I can fly.I believe I can touch the sky.Rhythm韵律A regular pattern ofstressandsyllablelength.Schwa:seestress.中元音Sentence stress:seestress.句子重音StressSentence stressis where different words in a sentence are stressed. In English these are usually theinformation-carrying words. In the sentenceIt was a lovely evening,and the temperature was perfect,themain stress, when spoken, is probably on the wordperfect. Stress can therefore be used to showmeaning,to emphasise a particular point or feeling.Strong/weak forms重读及弱读If the word is unstressed, theweak formof vowels may be used, e.g.Ican(/k n/)speak Italian,French,English and Spanish. The sound / / is called theschwa.If a word is important, then the strong form is used, and the pronunciation changes, e.g.I can(/kaen/)speak a little Spanish in an emergency.Word stressis the pronunciation of asyllablewith more force than the surrounding syllables which aresaid to beunstressed, e.g.umbrella.Sometimes, a word may have two stresses, in which case one syllable takes themain stress. In thewordindependent, for example ‘pen’ takes the main stress.Strong forms:seestress.Syllable音节A part of a word that usually contains a single vowel sound, e.g.pen= one syllable;teacher= twosyllables–teach/er;umbrella= three syllables–um/bre/lla._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 20058Unvoiced sound:seevoiced/unvoiced sound.Voiced sound/unvoiced sound浊音及非浊音A voiced sound is a way of pronouncing sounds with vibration (voiced) or without vibration (unvoiced) inthe throat. In English, vowels are usually voiced. Many sounds differ only because they are eithervoiced, e.g. /b/ or unvoiced, e.g./p/.Vowel元音One of the sounds shown by the lettersa,e,i,o uand sometimesy. Seeconsonant.Weak forms:seestress.Word stress:seestress.FUNCTIONS功能Candidates should already be familiar with common functions such asasking,telling,replying,thankingandsuggesting.Appropriacynounappropriate/inappropriateadj适合的Language which is suitable or correct in a particular situation. Seeregister.Colloquial口语的Language used ininformalconversations or writing.Declining, refusing an invitation拒绝邀请To refuse or decline an invitation, e.g.I’m sorry but I can’t.Enquiring要求To ask for information, e.g.What time does the train leave?Express表达式To show or make known a feeling or an opinion in words.Expressing ability, e.g.I can swim.表达能力Expressing intention, e.g.I’m planning to visit him next year.表达意图Expressing necessity, e.g.He needs to get a new passport.表达需求Expressing obligation, e.g.You must wear a seatbelt.表达职责Expressing permission, e.g.Can I have a look at your book?表达许可Expressing preference, e.g.I’d rather have coffee than tea.表达喜好Expressing probability, e.g.He should be in later.表达可能性Formal (language):seeregister.Formality (level of):seeregister.FunctionThe reason or purpose for communication, e.g.making a suggestion;giving advice.Functional exponentA phrase which is an example of a function and shows the purpose of the speaker, e.g.Let’s.... Thisphrase is one way to make a suggestion. It is an example (orexponent) of the function of suggesting.Seefunction.Greeting问候To welcome someone, often with words, e.g.Hello,how are you?Inappropriate:seeappropriacy._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 20059Informal (language):seeregister.Informality (level of):seeregister.InstructingTo order or tell someone to do something, e.g.Please turn to page 12 and do exercise 1.Negotiating协商用语To have a discussion with someone to reach an agreement, e.g.If you help me now,I’ll he lp you nextweek.Neutral中性语A style of speaking or writing that is neitherformalnorinformal, but in-between. It isappropriateformost situations.Predicting预测To say what you think is likely to happen, e.g.I think the story will end happily.RegisterThe formality or informality of the language used in a particular situation. Formal register or language isused in serious or important situations, e.g. in a job application. Informal register or language is used inrelaxed or friendly situations, e.g. with family or friends.Requesting,making a (polite) request提出要求To ask someone politely to do something, e.g.Please could you open the window?Speculating推测To guess something, e.g.I think it might be an easy test.Concepts and terminology for describing language skills对于描述语言技能的概念及术语Accuracy准确性The use of correct forms of grammar, vocabulary and pronunciation. In an accuracy activity, studentstypically give more attention to correctness. Seefluency.Authenticity:seeauthentic material.Context上下文1. The situation in which language is used or presented in the classroom.2. The words or phrases before or after a word which help a student to understand that word.Deduce meaning from context从上下文中推断意思To guess the meaning of an unknown word by using the information in a situation and/or around theword to help, e.g.I drove my van to the town centre and parked it in the central car park.Vanmust be some kind ofvehicle because youdriveit andparkit.Develop skills开发技能To teach students how to do activities like listening, and help them to understand how to listen.Draftnoun + verb,re-draftverb草拟，草案Adraftis a piece of writing that is not yet finished, and may be changed. A writer drafts a piece ofwriting. That is, they write it for the first time but not exactly as it will be when it is finished. When thewriting is changed, it isredrafted.Edit编辑To correct mistakes in a piece of writing, and perhaps shorten or change the words of some parts of thetext to make it clearer or easier to understand.Extensive listening/reading泛读、泛听Listening to or reading long pieces of text, such as stories. You may listen to or read some parts indetail and mayskimother parts. Seeintensive listening/reading.Extract摘录Part of a text._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 200510Fluency,oral fluency流利度The use of connected speech at a natural speed without hesitation, repetition orself-correction. In afluency activity,students typically give more attention to the communication of meaning, rather thancorrectness. Seeaccuracy.Infer attitude,feeling,mood感情及情绪To decide how a writer or speaker feels about something from the way that they speak or write, ratherthan from what they actually and openly say or the words they use.Intensive listening/reading精读，精听Reading or listening to focus on how language is used in a text. Seeextensive reading/listening.Interactionnoun,interactverb,interactive strategies互动Interact ion is ‘two-way communication’. Interactive strategies are the means used, especially inspeaking, to keep people involved and interested in what is said, e.g. eye contact, use ofgestures,functionssuch as repeating,asking for clarification.归类Layout布局The way in which parts of a text are organised and presented on a page. Certain texts have speciallayouts, e.g. letters and newspaper articles.Listen/read for detail阅读获得更多的细节To read or listen to a text in order to get meaning out of every word.Listen/read for gist主旨性阅读To read or listen to a text to understand its general meaning or purpose. Seeskim.Listen/read for mood情感阅读To read or listen to a text in order to identify the feelings of the writer or speaker. Seeinferattitude/feeling/mood.Note-takingnoun,take notesverbNote-taking is one of thesubskillsof writing. To take notes means to write down ideas in short form.Oral fluency:seefluency.Paragraphnoun + verb段落A paragraph is part of a longer piece of writing such as an essay, which starts on a new line and usuallycontains a single new idea. When a writer is paragraphing,he/she is creating paragraphs. Seetopicsentence.Paraphrasenoun + verb转述To say or write something in a short and clear way, using different words. If a learner is not sure of theexact language they need to use, they can paraphrase, i.e. explain their meaning using differentlanguage.Predictionnoun,predictverbA technique orlearner strategystudents can use to help with listening or reading. Students think aboutthetopicbefore they read or listen. They try to imagine what the topic will be or what they are going toread about or listen to.This makes it easier for them to understand what they read or hear.ProcessnounA series of actions performed in order to do, make or achieve something.Process writing写作流程An approach to writing, which looks at writing as aprocessand includes different stages of writing suchas planning,drafting,re-drafting,editing,proofreading.草拟，修改，编辑，校正Productive skills输出技能When students produce language. Speaking and writing are productive skills. Seereceptive skills.ProofreadTo read a text checking to see if there are any mistakes in spelling, grammar etc.Re-draft:seedraft.Receptive skills输入技能When students do not have to produce language; instead they read or listen to a text. Seeproductiveskills._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 200511Scan速读To read a text quickly to pick out specific information.Skill,subskill技能The four language skills are listening, speaking, reading and writing. Each skill can be divided intosmallersubskillsthat are all part of the main skill, e.g. identifying text organisation (reading); identifyingword stress(listening).Skim跳读To read a text quickly to get a general idea of what it is about.Subskill:seeskill.小技能Summarynoun,summariseverb归纳To take out the main points of a long text, and rewrite them in a short, clear way, using full sentences.Text structure文本结构The way a text is organised. For example, an essay typically has an introduction, main section andconclusion.Topic话题The subject of a text or lesson.Topic sentence主题句A sentence that gives the main point or subject of aparagraph. This is usually the opening sentence ina paragraph.Background to language learning语言学习的背景Achievable target,goal可以达到的目标An aim that is not too difficult for the learner to reach.Acquisitionnoun,acquireverb获取To learn a language without studying it, just by hearing and/or reading and then using it. This is the waywe all learn our first language.Attention span注意力集中时限How long a student is able to concentrate at any one time.Auditory learner:seelearning style.听觉学习者Cognitive (processes)认知过程The mental processes involved in thinking, understanding or learning.Confidence自信心The feeling someone has when they are sure of their ability to do something well. Teachers often doactivities that help students to feel more confident about their own ability.Conscious (of)意识到To know that something exists or is happening, or to have knowledge or experience of something; to beaware.Deductive learning演绎式学习方法An approach to learning in which students are first taught the rules and given all the information theyneed about the language. Then they use these rules in language activities. Seeinductive learning.Demotivate:seemotivation.失去学习动力Developmental error:seeerror.发展性错误Error错误A mistake that a learner makes when trying to say something above their level of language or languageprocessing.Adevelopmental erroris an error made by a second language learner which could also be made by ayoung person learning theirmother tongueas part of their normal development, e.g.I goed there lastweek(I went there last week).Seeslip._________________________________________________________________ _____________________________© UCLES Cambridge ESOL 200512Expectationnoun期望A belief that something will happen, e.g.He has an expectation that he will win.Exposurenoun,exposeverb暴露When learners listen to or read language without beingconsciouslyaware of it.Factor因素A fact or situation which influences the result of something, e.g. thefactorswhich decide whethersomeone learns a language successfully or not.First language:seemother tongue,L1.母语Focus on form注重形式To pay attention to language by identifying and practising it.Goals目标Aims that a student or teacher may have.Guidance指示Help given by a teacher with learning, or with doing atask.Ignore (errors)忽略错误To choose not to pay attention to something such as anerrormade by a student.A teacher may do thisif they want to help the student withfluency, notaccuracy.Independent study独立学习Studying without a teacher present. This can be done at home, in a library etc.Inductive learning引导式学习An approach to learning in which students are not first taught the rules of grammar. Theywork outtherules for themselves by using the language. Seedeductive learning.Interference干涉When the learner’smother tongueinfluences their performance in thetarget language. A learner maymake a mistake because they use the same grammatical pattern in the target language as they use intheir mother tongue.TheL1grammatical pattern is notappropriateinL2.Interlanguage中间语Learners’ own version of the second language which they speak as they learn. Interlanguage isconstantly changing and developing as learners learn more of the second language.Kinaesthetic learner:seelearning style.运动感觉学习者L1/L2母语/第二语言L1 is the learner’smother tongueor first language; L2 is the learner’s second or other nguage awareness语感Understanding the rules of how language works.Learner autonomynoun,autonomousadj,learner independence学习自主性When a student does not need a teacher to learn, but can set their own aims and organise their ownstudy they areautonomousand independent. Many activities in coursebooks help students to be moreindependent by developing独立的learning strategiesandlearner training.学习技巧Learner characteristics学习者特性The typical things about a learner or learners that influence their learning, e.g. age,L1, past learningexperience,learning style.学习类型Learner independence:seelearner autonomy.独立学习Learner training培训The use of activities to help students understand how they learn and help them to become independentlearners.Learning resources学习资源The materials or tools which help students learn, e.g. books, computers, cassettesetc.__________________________________________________________________ ____________________________© UCLES Cambridge ESOL 200513Learning strategies学习技巧。