ORFEUS II echelle spectra The scale height of interstellar O VI in the halo

小学上册英语第一单元期中试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The __________ (历史的动态变化) shape perceptions.2.What do we call the study of cancer?A. OncologyB. PathologyC. HematologyD. Epidemiology3. A _____ (生态平衡) is essential for a healthy environment.4.We go _____ (birdwatching) in the park.5.The golden retriever is a popular _________ (宠物).6.What is the name of the fairy tale character who wears a red cape?A. CinderellaB. Snow WhiteC. Little Red Riding HoodD. Rapunzel7.We are learning about ______ (historical) events.8.The __________ is a region known for its heat and dryness.9.Chemical reactions can be represented using ________ equations.10.What is the largest ocean on Earth?A. AtlanticB. IndianC. PacificD. Arctic11.The turtle can retract its limbs into its ______ (壳).12.The bear hibernates during the _______ (冬天).13.My ________ (玩具名称) is a reminder of my childhood dreams.14.The freezing point of water is _____ degrees Fahrenheit.15.The study of E arth’s history helps us understand ______ changes.16.What do you call a person who collects stamps?A. PhilatelistB. CollectorC. DealerD. HistorianA17. A ______ (植物资源管理) is vital for sustainability.18.ts have _____ (多样性) in their shapes. Some pla19. A dolphin is very ______ and friendly.20.The _____ (seashell) is pretty.21.The ________ (cactus) grows in the desert.22.What is the capital city of Canada?A. TorontoB. OttawaC. VancouverD. MontrealB23.The chemical symbol for silicon is ______.24.What do you call the place where you can watch live performances?A. TheaterB. GalleryC. MuseumD. ArenaA25.Martin Luther King Jr. is known for his role in the ________ movement.26.What do we call a flower that blooms in spring?A. DaisyB. RoseC. TulipD. All of the above27.The ancient Sumerians created one of the first known ________.28.The ______ is always smiling and kind.29.Which fruit is yellow and curved?A. AppleB. BananaC. OrangeD. Mango30.The cat is _____ (small/big).31.What is the largest mammal in the ocean?A. SharkB. WhaleC. DolphinD. OctopusB32.The _____ (forest) is dense.33.I want to _______ (学会) how to sew.34.I play chess with my __________. (父亲)35.I see a _____ (彩虹) in the sky.36.What do you call a group of fish?A. SchoolB. PackC. FlockD. SwarmA37.The chemical formula for sodium oxalate is ______.38.I saw a ________ playing in the grass.39.What do we call the celebration of a new year?A. HalloweenB. ThanksgivingC. Ne w Year’s EveD. Christmas40.What is the term for the layers of gases surrounding the Earth?A. AtmosphereB. LithosphereC. HydrosphereD. BiosphereA41.The sky is ___ (clear).42.What is the opposite of "new"?A. FreshB. OldC. YoungD. Modern43.What do we call a story that is passed down through generations?A. FableB. LegendC. MythD. All of the aboveD44.What do we call the study of the human mind?A. PsychologyB. SociologyC. PhilosophyD. AnthropologyA Psychology45.小刺猬) rolls away when threatened. The ___46. A ______ can be found in many colors.47.What is the name of the famous British rock band known for songs like "Hey Jude"?A. The BeatlesB. The Rolling StonesC. Pink FloydD. Queen48. A ____ is known for its long ears and quick movements.49. A snail moves very ______.50.What is the name of the famous American author known for "The Road"?A. Cormac McCarthyB. Don DeLilloC. Philip RothD. Toni MorrisonA51.What do we call a place where you can buy books?A. LibraryB. BookstoreC. MarketD. SchoolB52.The rabbit hops quickly in the _______ (兔子在_______中快速跳跃).53.Insects are important for the _____ (授粉) process.54.The garden is _______ (生机勃勃).55.The __________ (历史的故事情节) captivate our imagination.56.How many days are in a week?A. 5B. 6C. 7D. 8C57.The Earth's crust is made up of various geological ______.58.My dad is a skilled __________ (技工).59.The snake sheds its _______ (皮肤) regularly.60.The main component of air is __________.61.What is the color of a ripe banana?A. RedB. BlueC. YellowD. Green62.My toy ____ can swim in the pool! (玩具名称)63.The _____ (果酱) can be made from fresh berries.64.The _______ of an object can change when it moves.65. A simple sugar is known as a _____ (monosaccharide).66.We have a ______ (精彩的) plan for the upcoming festival.67.My dad teaches me about __________ (责任感).68.My toy _____ can move its arms and legs.69.历史上，有许多________ (explorers) 冒险寻找新的土地。

小学上册英语上册试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.I love reading ______ (漫画) because they are fun and ______ (有趣).2.The dog is ___ (barking/growling).3.What is 3 x 3?A. 6B. 7C. 8D. 94.The playground is ______ (fun) to play in.5.I hear a ___. (bell)6. A mixture can be separated using physical ______.7.The __________ is a famous canyon in Arizona. (大峡谷)8.My favorite animal is a ______ (猫) because they are gentle.9.What is the capital of Sweden?A. OsloB. StockholmC. CopenhagenD. HelsinkiB10.The pH scale measures how __________ or basic a solution is.11.The main purpose of fats is to store _____.12.The ______ (生态保护) helps prevent extinction.13.I like to dress up my _________ (洋娃娃) in different styles.14.What is the primary color of the ocean?A. BlueB. GreenC. BrownD. YellowA15.Which season is after summer?A. WinterB. SpringC. Fall (Autumn)D. Summer16.The ancient Romans created a complex ______ (社会) structure.17.I enjoy playing outside when it’s __________. (愉快的)18.We will have _____ (fun/work) at the park.19.What do bees make?A. MilkB. HoneyC. ButterD. JamB20.We go to school ___ (by/with) bus.21.What do you call the process of water falling from the sky?A. EvaporationB. CondensationC. PrecipitationD. TranspirationC22.The _____ (香味) of the flowers is wonderful.23.My favorite flower is a ______.24.What is the first month of the year?A. JanuaryB. FebruaryC. MarchD. AprilA25.The leaves on the _______ turn green in spring.26. A _______ is a process that occurs in nature.27.The sun is ______ brightly during the day. (shining)28. A ____(community development strategy) fosters growth and empowerment.29.What is the opposite of ‘true’?A. RealB. FalseC. CorrectD. Right30.The chemical formula for -pentanoic acid is ______.31.What is the name of the famous giant redwood tree in California?A. General ShermanB. Redwood National ParkC. SequoiaD. Giant Sequoia32.What is the largest mammal?A. ElephantB. Blue WhaleC. GiraffeD. Hippo33.We watch ________ (documentaries) about nature.34.The _______ can help create a welcoming atmosphere.35.The ______ (小鸟) takes flight as soon as it learns to spread its ______ (翅膀).36.The otter uses rocks to crack open _______ (贝壳).37. A _____ (植物分类) can help identify species.38.I have a _____ of chocolate in my bag. (bar)39.My dad, ______ (我爸爸), enjoys woodworking and crafts.40.What color do you get when you mix red and white?A. PinkB. PurpleC. OrangeD. BrownA41.Earthquakes occur when there is a sudden release of __________ in the Earth's crust.42.My cousin is a ______. She loves to create videos.43. A small ___ (小袋鼠) hops around in Australia.44.The first woman to win a Nobel Prize in Physics was _______. (居里夫人)45.Which flower is known for being red?A. TulipB. RoseC. DaisyD. SunflowerB46.The invention of the steam engine was a major development in the ________ Revolution.47.What is the name of the famous painting by Salvador Dalí?A. The Persistence of MemoryB. The Last SupperC. GuernicaD. The Scream48.What do you call a young female kangaroo?A. JoeyB. CalfC. KitD. PupA49.They play _____ (football) after school.50.I love my _____ (毛绒玩具) that is soft.51.How many stars are on the flag of the United States?A. 50B. 48C. 52D. 54A 5052.I enjoy _______ (写故事).53.What do we call a young female horse?A. ColtB. FillyC. FoalD. CalfB Filly54.The book is _______ (有趣的) to read.55.My sister enjoys __________ (参加) workshops and classes.56. A mixture that has a variable composition is called a _______ mixture.57.Acidic solutions have a pH less than _______.58.I enjoy building ______ (积木) towers with my little brother.59.What do we call the outer layer of the Earth?A. CrustB. MantleC. CoreD. ShellA60.The _____ (花坛) can attract bees and butterflies.61.What is the color of snow?A. BlackB. BlueC. WhiteD. Green62.What do you call a place where you can borrow books?A. LibraryB. BookstoreC. SchoolD. MuseumA63.My sister is my best _______ because we have so much fun together.64.The process of ______ can lead to the discovery of valuable minerals.65.global warming) affects climates worldwide. The ____66.The kitten is ________ and soft.67. A _____ (鲸鱼) can sing songs underwater.68. A ____ is known for its hopping and is often found in gardens.69.What do we call a scientist who studies the properties of matter?A. BiologistB. ChemistC. PhysicistD. GeologistB70. A physical change does not alter the ________ of a substance.71.My cousin is a wonderful __________ (舞者).72.The chemical formula for table sugar is _______.73.What is the first month of the year?A. FebruaryB. JanuaryC. MarchD. AprilB74.Which food is a fruit?A. CarrotB. PotatoC. BananaD. LettuceC75.What do you call the process of removing waste from the body?A. DigestionB. ExcretionC. RespirationD. Circulation76.The chemical formula for ammonia is _____.77.My dad teaches me to be __________ (有责任感的).78.What is 5 + 5?A. 9B. 10C. 11D. 1279.What do you call a book containing words and their meanings?A. EncyclopediaB. DictionaryC. AtlasD. ManualB80.The chemical formula for calcium fluoride is __________.81.Which animal is known for its stripes?A. ZebraB. LeopardC. CheetahD. TigerA82.Planting trees along streets can provide ______ from the sun. (在街道上种植树木可以提供遮阳。

小学上册英语第二单元真题(有答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.I enjoy learning about ________ in science class.2.The _____ (pond) is calm.3.Have you ever seen a _______ (小老鼠) eat cheese?4.What do we call the study of plants?A. BiologyB. BotanyC. ZoologyD. Ecology答案: B5.The __________ (历史的框架) shapes understanding.6.She is a _____ (翻译) who speaks multiple languages.7. A period in the periodic table represents elements with the same number of ______.8.The _____ (植物) needs water.9.I like _____ (chocolate/vanilla) ice cream.10. A ________ (冰川) can create valleys as it moves.11.I love wearing my __________ when it snows. (厚外套)12. A ________ (湖泊) can be fresh or saltwater.13.My teacher encourages us to be polite by calling her ______. (我的老师鼓励我们通过称呼她为____来表现礼貌。

)14.What do we use to write?A. BrushB. PencilC. HammerD. Spoon答案: B15.The flowers smell ______ (sweet) in spring.16.The Earth's surface is shaped by both climatic and ______ factors.17.What is the opposite of "sweet"?A. BitterB. SourC. SaltyD. Spicy答案: A18.The Mississippi River flows through __________.19.My toy ________ can move by itself.20.What is the opposite of "fast"?A. SlowB. SmallC. HighD. Long答案:A Slow21.The baby is in the ___ (crib/chair).22.My favorite cereal is _______ (我最喜欢的谷物是_______).23.Galaxies can collide and merge with ______.24.World War II began in __________. (1939年)25.The chemical formula for potassium sulfate is ______.26.In winter, it gets very ______ (冷) and sometimes it snows. I love to make a ______ (雪人) and ______ (打雪仗) with my friends.27. A _______ is a device used to measure the concentration of a solution.28.The teacher is very ________.29.I enjoy cooking simple meals like ________ (意大利面) and ________ (沙拉) with my family.30.Metallic elements are usually good ______ of heat.31.The bee buzzes around the ______.32.My brother, ______ (我弟弟), loves to play chess.33.The chemical symbol for antimony is ______.34.The tortoise moves very _______ (慢).35.We will go ________ (海边) this summer.36.She is ___ (good/bad) at math.37. A __________ is a city that is not the capital but is important for trade.38.The goldfish swims to greet me when I arrive with ______ (食物).39.The process of ______ involves the breaking down of rocks into smaller pieces.40.The owl has specialized ______ (视觉) for seeing in darkness.41. A dilute solution contains a small amount of ______.42.What is the name of the mountain range that separates Europe and Asia?A. AndesB. HimalayasC. RockiesD. Ural Mountains答案:D43.My ________ (玩具) is fun to play with alone or with friends.44.I have two ___ and one brother. (sisters)45. A ______ (植物博物馆) can educate visitors about species.46.The Earth's atmosphere is vital for supporting ______.47.What is the main ingredient in a salad?A. MeatB. VegetablesC. RiceD. Bread答案:B48.My dad is a _____ (医生).49.My favorite activity is ______ (旅行).50.The ________ (土壤) is rich for farming.51.The ________ (城市功能) serves many needs.52.The __________ (古代波斯) was known for its great emperors.53.My dog likes to chase ______ (球).54.I enjoy _______ (看电视) after dinner.55. A heterogeneous mixture has visibly ______ components.56.The __________ (法兰西帝国) was established by Napoleon Bonaparte.57. A _____ (雨林) has many layers of vegetation.58. A solvent is the substance that dissolves a ______.59.My grandmother makes the best __________. (蛋糕)60.I like to collect ________ (玩具名称) from my favorite shows.61. A frog can jump _______.62.environmental psychology) studies human interactions with nature. The ____63.The __________ (历史的启迪) guides our journey.64.What is the name of the famous scientist known for his work on the laws of thermodynamics?A. Rudolf ClausiusB. Lord KelvinC. Albert EinsteinD. James Clerk Maxwell答案: A65.He is _______ at playing soccer.66. A solution is created when a solute is ______ in a solvent.67.My brother is a great ________.68.I have a _____ (gift) for you.69.What is the scientific name for the common house cat?A. Canis lupusB. Felis catusC. Ursus arctosD. Equus ferus答案:B70.The ______ (小龟) is very slow.71.My cousin is a ______. She loves to travel.72.The process of a liquid turning into a gas is called _______.73.My ________ (玩具名称) helps me learn about history.74.The country famous for its castles is ________ (法国).75.The chemical formula for calcium chloride is _______.76.The _______ (The Space Shuttle) program enabled human spaceflight.77.The __________ Mountains are found in North America. (落基山)78.I have a ________ (玩具火箭) that I pretend to launch into space.79.The chemical symbol for magnesium is ____.80.The process of sublimation is when a solid changes directly to a _____.81.I like to _____ at the park. (play)82.The _____ (画) is stunning.83.What do we call the area of land that is covered by vegetation?A. FloraB. FaunaC. BiomeD. Ecosystem答案: C. Biome84.The first man to reach the North Pole was _______. (皮尔·阿蒙森)85. A __________ is formed when sediments are compacted over time.86.In the winter, I love to go __________. (滑雪)87.My ______ is very adventurous.88. A ______ can be trained to help humans.89. (Pledge) of Allegiance was written in the 19th century. The ____90.The chemical reaction that occurs in batteries is an example of a _____ reaction.91. A zebra is known for its black and ______ stripes.92. A __________ is an area of land rich in resources.93.The car is ___. (fast)94.I can ______ (sing) a song for you.95.Many plants are ______ (适应性强) to their surroundings.96.The process of ______ can cause landslides and avalanches.97.The ________ (气候变化影响) is studied globally.98.The ancient Egyptians had a god for _______. (每个方面的生活)99. A __________ has a long neck and legs, often found in Africa.100.I like to organize my ________ (玩具) collection.。

小学上册英语第四单元真题(含答案)英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1. (Sumerians) invented one of the first writing systems. The ____2.I love to listen to ______ (音乐) while doing homework.3.The __________ (亚历山大大帝) created one of the largest empires in history.4.The ______ is known for its strength and size.5.My favorite ice cream flavor is ________ (巧克力).6. A __________ (植物园) showcases many types of plants.7.An acid-base indicator changes color at a specific _____.8.The sky is ________ and clear.9.The ________ (presentation) was engaging.10.I like to ___ with my friends. (play)11.The ant's colony is usually found underground in a _______.12.The squirrel collected ______ for winter.13.My dad _____ the car every Sunday. (washes)14.The platypus is unique because it lays eggs and has ______ (毒腺).15.The process of changing from a solid to a liquid is called _______.16.The frog jumps into the ______ (水). It makes a big ______ (水花).17.The finch sings a beautiful ________________ (歌).18.I like to play ______ (soccer) with my friends.19.My mom loves to create ____ (recipes) for the family.20.The chemical formula for sodium bicarbonate is _______.21.My ________ (玩具名称) is a superhero that saves the day.22.The roots help the plant to __________ (吸收) water.23.My brother loves to build with ____ (Legos).24.The fire is ___ (crackling).25.I have a toy _______ that can make sounds.26. A chemical property describes how a substance _____ with others.27.The __________ is a body of water that is part of the ocean.28.The tiger roars loudly in the _________ (丛林).29.What is 20 divided by 4?A. 3B. 4C. 5D. 6答案: C30.The process of melting occurs when a solid becomes a _______.31.The main component of the ozone layer is ______.32.The elephant's ears help to regulate its ________________ (体温).33.I enjoy ________ (走路) in the park.34.My sister is ________ her friends.35.The capital of Spain is ________.36.The ________ (balloon) is floating up.37.The _______ (青蛙) is often found near water sources.38.At school, I enjoy __________. It allows me to express my creativity and learn new skills. My favorite project was __________ because I had so much fun working on it.39.Birds can _______ in the sky.40.Chemical equilibrium occurs when the rates of forward and reverse reactions are______.41.Each toy has its own special ____. (特点)42. A ______ is a geographical formation that influences weather patterns.43.The _____ (sapling) will grow into a strong tree.44.My sister is a ______. She loves fashion design.45. A hamster runs fast on its ______ (轮子).46.My sister loves to __________ (学习) new things every day.47.The park is ______ (a great) place to relax.48.I enjoy ______ (与同龄人社交).49.The sun is ________ (温暖) in spring.50.The teacher is _____ (kind/strict) to us.51.What is the name of the large mammal known for its trunk?A. LionB. GiraffeC. ElephantD. Rhino答案: C52.The flowers in the garden attract _______ and happy bees.53.He is drawing a ___. (picture)54.The ______ (花瓣的颜色) can signal to pollinators.55.The speed of sound is faster than the speed of _______.56.What do you use to measure time?A. RulerB. ClockC. ScaleD. Thermometer答案:B57. A reaction that produces a precipitate is called a ______ reaction.58.The _____ (lake/ocean) is blue.59.I wear a coat in the ___. (winter)60. A chemical reaction can lead to the formation of new ________.61.The _______ is often seen in fairy tales.62.The capital of Cyprus is __________.63.The __________ is an important region for agriculture. (平原)64.The ancient Romans used ________ as a form of entertainment.65.nts can grow in _____ (容器) indoors. Snakes _66.What is the main language spoken in the USA?A. SpanishB. FrenchC. EnglishD. Chinese答案: C67.I enjoy ______ (与家人一起) going to the beach.68.The __________ is a region known for its fjords.69.The ancient Greeks developed the concept of ________ (逻辑).70.I love collaborating on projects because it combines our __________.71.ts are used for __________ (装饰). Some pla72.The manager, ______ (经理), organizes the team.73.Sound travels through _______ like air or water.74.Gardening can be a rewarding ______ that connects people with nature. (园艺是一项有益的活动，可以将人们与自然联系起来。

arXiv:h ep-la t/931235v18Dec1993Glueball Spectra of SU(2)Gauge Theories in 3and 4Dimensions:A Comparison with the Isgur-Paton Flux Tube ModelT.Moretto NORDITA Blegdamsvej 17DK-2100Copenhagen Ø,Denmark and M.Teper All Souls College and Department of Physics University of Oxford 1Keble Road Oxford OX13NP,UK AbstractCurrent lattice calculations(1−4)of the SU(2)spectrum in3+1dimensions are accurate, have a good control offinite-volume corrections,and have been performed down to verysmall values of the lattice spacing,a.This should encourage us to see whether an accurate extrapolation to the continuum limit is possible.Similar calculations(5)in2+1dimensionsare even more accurate and some such extrapolations have already been made in that case. In both dimensions the theories are believed to possess linear confinement at large distancesand they become free at short distances.These similarities suggest that a comparison of the respective mass spectra should be informative.However there is a limit as to howfocussed our comparison of the spectra can be if posed in the abstract.To do better it will clearly be very useful to have a model framework within which to couch the discussion.We can then hope to pin-point which dynamical features of the model work in practice and which do ing two different spatial dimensions provides an extended lever armfor the comparison.In return we can expect that the model will focus our attention on what are the weak points of current lattice calculations.Glueball models are more speculative than models for the usual hadrons,where at least the basic starting point,valence(constituent)quarks,is well established.We are aware oftwo models that might be useful for our purposes here:the bag model(6)and theflux tube model(7).In this paper we shall work with theflux tube model.A detailed comparisonwith the bag model would also be of interest.However in that case there is a complication -the lightest0+state has an imaginary mass once the centre of mass motion is subtracted-and it is not clear to us to what extent the usual resolution of this problem should beconsidered uncontroversial.We turn now to the lattice glueball ttice masses always come in lattice units and so,to remove the lattice spacing,we will consider ratios of masses.In general themost accurately calculated physical quantity is the string tension,σ.Therefore the mass ratios that we shall extrapolate to the continuum limit will be of the form m/√σwhere m is a glueball mass.Now the leading lattice correction to such a mass ratio is known tobe of the form(8)O((a/ξ)2)whereξis some physical length scale.We choose to use the √σin which case this leading correction is proportional to a2σ.(This length scaleξσ=1/correction may also contain a dependence on g2but this varies weakly,if at all,with a and so we neglect it.)We nowfit the D=4lattice results(1−4)in the rangeβ≡4/g2≤2.85 with a formula that incorporates this correction and we obtain the continuum mass ratios shown in the relevant column of Table1.For D=3we perform an identical analysis on the results of ref(5),for the rangeβ≡4/ag2≤14.5,and we obtain the second column of Table1.To be confident in these results requires a rather detailed analysis of the mass calculations at each value ofβ.This will be provided in a longer paper(9).That paper will also contain a careful description of theflux-tube model,which we only sketch here,and it will contain a much more comprehensive comparison of spectra than we are able to provide in this Letter.One point of detail that we are forced to address here is the spin assignment.The glueballwave-functionals are constructed using only the lattice rotational symmetries.Thus a state that we call J=0may actually be J=4,8,...The usual practice is to label the state bythe lowest allowed value of J on the assumption that that is presumably the lightest of the contributing states.Our analysis of theflux-tube model will show that this assumptionbreaks down too often for it to be really useful.Fortunately one can easily show(9)that where the basic components used in constructing the glueball wavefunctionals are broadand smooth-as are the smeared operators used in those lattice calculations whose results we employ-the lattice operator will have its largest individual projection onto the statewith the lowest allowed J.One can therefore infer that when we extract the lightestmass contributing to the correlation function of such smeared operators,if the normalised projection of the operator onto this lightest mass state is much greater than0.5,then it isextremely unlikely that that state possesses anything other than the lowest allowed value of J.By this criterion all the spin assignments in Table1are correct and should be takenat face value.Before turning to the model it is interesting to compare the two spectra in Table1.What is most striking is how similar they are,taking into account that in3dimensions J=0states of opposite parity should be degenerate-which is what we observe(within errors). For both dimensions the lightest state is the0+and the next lightest is the2+,with the2−and0−not too far away.Then come the heavier states of spin J=1,3.Even the ratios of the2+to0+masses are not very different.The0+glueball is heavier in D=3than D=4when expressed in units of the string tension and we might wonder whether this can be simply related to the change in the number of spatial dimensions.As we shall see below,theflux-tube model does provide an explanation of this kind.In theories with linear confinement one expects theflux between well separated fundamen-tal sources to be localised in a stringlikeflux-tube.If one considers aflux-tube that closes upon itself rather than ending on quarks,then we have a colourless,quarkless‘excitation’which we can imagine providing us with the basic component of a glueball state.This is the starting point of the Isgur-Patonflux-tube model(7).We shall begin with the D=2+1case.Consider as our starting point a circularflux-loop of radiusρlying in the spatial plane.If we ignore the internal structure of the loop,then its oscillations are of two types.First there are the periodic oscillations about this circle. Secondly there are the‘collective’radial oscillations of the whole loop.The oscillations of thefirst type,upon quantisation,are described by phonons,of frequency m/ρ.We can define them so that they have angular momentum±m.Let n+m,n−m be the number of phonons with frequency m/ρand with J=±m respectively.Then the total angular momentum contributed by the phonons isJ= m m n+m−n−m (1) and the total excitation energy will be E=M/ρwhereM= m m n+m+n−m (2) In D=3parityflips angular momentum so it corresponds to interchanging the+and −phonons.Now,infinitesimal m=1oscillations are easily seen to be equivalent to infinitesimal translations and rotations.Thus we shall follow ref(7)and exclude these modes from consideration.This is analogous to the cm momentum subtraction in the bag model that we referred to earlier.Since these are simple harmonic oscillators they contribute a zero point energy,and this clearly diverges.The divergent piece is proportional to the string length and can be absorbed into the bare string tension to produce the observed string tension,σ.For long strings the leading remaining piece is simply13π(D−2)/6l where l is the string length2πρ.We recognise this as being the usual L¨u scher universal string correction(10,11)with the contribution of the m=1mode removed.Finally we put in a factor to soften the1/ρbehaviour because we know that the string is really aflux-tube with a width of order1/√σ.Putting all this together we can write the total energy of the string asM−γE M s(ρ)=2πρσ+d216πσspectrum is thenfixed(forfixed values ofγand f).So there is no obvious‘limit’where the adiabatic assumption becomes manifestly accurate.This is unlike the case with quarks where we can consider the limit of large quark masses.It is more-or-less obvious that in such a one-scale problem we should not expect the adiabatic assumption to be very good and so it would be pointless to look for a perfectfit between the model predictions and the real world of Table1.What we should rather do is to identify those parts of the spectrum where there is reasonable agreement and to try and relate any(dis)agreement to particular aspects of the model’s dynamics.We can also test the adiabatic assumption self-consistently.If it held very well then we would normally expect the splittings due to the phonon excitations to be much larger than the splittings due to radial excitations.In Fig.1we show a typical example of the masses of states of various radial,n,and phonon,M,quantum numbers.We see that the phonon and radial excitations lead to similar energy splittings.This tells us that the adiabatic approximation,while not necessarily very poor,is likely to be rather crude.A similar situation is found to hold in4dimensions.In fact in that case we have(13),from ref(4),a mass estimate for thefirst0+excited state and it is very close in mass to the lightest2+, just as predicted by the model.(This is a result at one value ofβand so has to be taken cautiously.)We show in Fig.2the lowest states of the model as functions of the parameter f and for two values ofγ(including the theoretically favoured value).The lightest state is the circular loop with no phonons which is clearly0+.The phonon states provide the J=0states which are parity doubled.On each of these states we have a tower of radial excitations with the same spins and parities.Since we exclude phonons with m=1it is clear that thefirst J=0states above the0+will have J=2,from one m=2phonon.To obtain J=1we need a phonon content of,for example,n+3=1and n−2=1;and so the state will be considerably heavier.All this is qualitatively like the actual spectrum summarised in√σis quite close to its Table1.Moreover,as we see in Fig.2,the predicted value of m(0+)/observed value,if we choose f near its expected value of unity.However the0−glueball, which requires large M,e.g.n+4=1and n−2=2,is predicted to be considerably heavier than the J=1states and this is contrary to Table1.Indeed it is only near f=1that the0+,0−states are in quantitative agreement with the spectrum in Table1and in that case the J=1,2states are much too light.However if we look(9)at the wave-functions of the states we see that the J=0states in particular are localised near smallρ-which is why they are so sensitive to the value of f at small f-and for such states the string picture is likely to be least reliable.Which brings us back to our earlier observation that it surely makes no sense to be searching for an exact agreement between the model and the real world.In Fig.2we also show the predictions of the model for the lightest J=3and J=4states. We observe that the4−is lighter than the0−and that the J=3state is lighter than the J=1state.This highlights how dangerous is the usual assumption that underlies the choice of labelling of states calculated on the lattice.The fact that the predicted4−is so close to the observed‘0−’,makes the question of whether,in fact,this latter state mightnot be4−particularly important.As we said earlier,we believe that there are convincing arguments to show that this is not the case.We now turn to the model in4dimensions.There are two additional types of oscillation. Thefirst consists of periodic vibrations orthogonal to the plane of the loop.This leads, upon quantisation,to an additional kind of phonon.The zero-point energy is doubled and so the theoretically favoured value ofγbecomes13/6rather than13/12as in3dimensions. The second additional type of oscillation is associated with the collective rotation of the plane of the loop.In the model this is assumed to be a‘slow’fluctuation and hence one that enters the Schrodinger equation through the addition of a familiar angular momentum term.The states produced purely from phonons will still possess parity doubling and it is these collective angular excitations that allow the D=4spectrum not to be parity doubled for many values of J.If the adiabatic approximation was very good then the lightest J=0 states would consist of angular excitations of the0+ground state and we would expect much smaller energy splittings than in D=3.However in practice the angular excitation energy is comparable to the basic phonon excitation energy,just as we found for radial excitations,and so it is not clear how these new excitations will alter the spectrum.We show in Fig.3the calculated spectrum in4dimensions as a function of f and for two values ofγ,including the theoretically favoured value ofγ=13/6.For values of f close to unity the spectrum resembles,at least qualitatively,the observed spectrum.That is, the lightest state is a0+with the2+,2−,0−states next,and J=1,3forming a heavier cluster of states.Indeed at f≃1the agreement is quite good even at the quantitative level.In D=4the two kinds of phonons allow us to have a lighter0−than in D=3.A striking prediction of the model that seems to hold for all values of f andγis that the J=3states are parity-doubled,unlike the J=1states that are somewhat heavier in the model.Unfortunately these states possess large errors in the current lattice calculations and so we cannot test these predictions at present.√σis larger by about We return now to our earlier observation that the mass ratio m(0+)/25%in D=3than in D=4.As we see in Table1there seems to be some such upward rescaling for the low-lying spectrum as a whole.It turns out that this phenomenon has a very simple origin in theflux-tube model.This can be seen if we compare the D=3and D=4spectra for the string values ofγ,as in Fig.2b and Fig.3b respectively.We observe that the0+mass ratio is indeed larger in D=3and that for f≃1the values are close to those in Table1.If on the other hand we compare the D=3and D=4spectra at the same value ofγwe see very little difference.Thus the origin of the difference lies in the factor of two difference between the values one calculates forγin3and4dimensions.This arises from a factor of two between the zero-point energies in3and4dimensions.This in turn follows from the fact that in3spatial dimensions there are twice as many types of transversefluctuation for the string as compared to2spatial dimensions.So the point is that the zero-point energy reduces the energy density of a string offinite length,as in a glueball,from the value ofσ,and the reduction is twice as great in D=4because there are twice as many transverse directions in which the string can oscillate.This argument is a rigorous one for the lowest-lying0+state because for that state it is only through thevalue ofγthat the dimensionality enters the calculation.Moreover it is clear that this is an effect that will apply to any glueball state that is composed of a smallflux loop.Theflux-tube model does surprisingly well in reproducing the overall features of the spec-tra,in both3and4dimensions.Perhaps its main weakness is that it predicts the0−to be always heavier than the1±in D=3.On the other hand one might regard the fact that the J=1states are heavier than the J=2states as a surprise and so the fact that the model reproduces this feature is a success for it.In the model it arises from the absence of phonons with m=1and from the fact that theflux loop has no direction for SU(2). The latter is no longer the case for SU(3)and will pose a problem for the model because the D=4lattice SU(3)spectra do not show any light J=1states.(However we leave the SU(3)comparison till the D=3spectra become available.)In the model it is the phonon excitations that naturally produce parity doubling.So the D=4spectrum will display parity doubling for those quantum numbers where the phonon states are the lightest ones-such as J=3.This prediction tests the fundamental dynamical assumptions of the model.It is unfortunate that the lattice results are still too poor,for such heavier glueballs,to test this prediction.Of course the basic assumption of the model is that glueballs are essentiallyfinite loops offlux.One may view it as significant that this provides a very simple explanation for the observed fact that,when expressed in units of the string tension,the lowest lying glueballs are lighter in4than in3dimensions. The comparisons with theflux-tube model have focussed attention on features of the spectrum that might otherwise have appeared to be without any special significance.In particular it has focussed attention on some things that lattice calculations need to do better.For example it is crucial that we be confident in the continuum spin assignments for states on the lattice;and it is also important to calculate the masses of states such as the J=4etc.Indeed the time has come to construct lattice wave-functionals that are good approximations,up to corrections of O(a2)say,to states of a particular continuum J.There is no real difficulty in doing so.It is also clear that it is not only the lowest-lying states of any given J P that are important;the excitations carry valuable information,in this model,about the splittings due to the‘collective’radial and angular excitations.The energies of such states are easily calculable in lattice calculations although it has usually not been thought important to do so and almost no published results exist.Finally heavier states,such as the J=3states in4dimensions,can also be important,as was pointed out in the previous paragraph.On the lattice these are most easily calculated by working with small lattice spacings.This will be time-consuming but not outrageously so.AcknowledgementsWe are grateful to Jack Paton for very helpful discussions.We acknowledge the Oxford Particle Theory Grant SERC GR/F/41501.One of us(TM)is grateful to the Danish Natural Science Research Council forfinancial support during part of this work.ReferencesFig.1:The D=3glueball spectrum as a function of f and for the values ofγindicated. The column of points at the far right comes from Table1.Other points display the values obtained with the model.The lines are to guide the eye.The dashed line is for the0−. Fig.3This figure "fig1-1.png" is available in "png" format from: /ps/hep-lat/9312035v1This figure "fig2-1.png" is available in "png" format from: /ps/hep-lat/9312035v1This figure "fig1-2.png" is available in "png" format from: /ps/hep-lat/9312035v1This figure "fig1-3.png" is available in "png" format from: /ps/hep-lat/9312035v1。

小学下册英语第2单元测验试卷考试时间：80分钟（总分:100）A卷一、综合题(共计100题共100分)1. 听力题：The Earth is located in the Orion ______.2. 听力题：The chemical symbol for selenium is ______.3. 选择题：What do we call the force that pulls objects toward each other?A. MagnetismB. GravityC. FrictionD. Tension答案:B4. 填空题：I can ______ (灵活应变) to new challenges.5. 听力题：Chemical reactions can be classified as synthesis, decomposition, and _____.6. 选择题：What is the main ingredient in oatmeal?A. RiceB. WheatC. OatsD. Corn答案:C. Oats7. 选择题：What do we call the time when schools are closed for summer?A. HolidayB. VacationC. BreakD. Session8. 听力题：Endothermic reactions require energy, usually in the form of ______.9. 选择题：What do you call a person who helps in an emergency?A. TeacherB. ParamedicC. ChefD. Driver答案:B10. 填空题：A _____ (章鱼) can squirt ink to escape danger.11. 听力题：The Battle of Hastings took place in the year ________.12. 选择题：What do you call the part of the plant that absorbs water?A. LeafB. StemC. RootD. Flower答案:C13. 填空题：A ______ (生态系统服务) is crucial for human well-being.14. 选择题：What do we call a person who plays a musical instrument?A. MusicianB. ComposerC. ConductorD. Singer答案: A. Musician15. 填空题：The _____ (户外) is a perfect place for a picnic among the flowers.16. 填空题：The kangaroo uses its powerful legs to ______ (跳跃).17. 填空题：A monkey can _______ (爬) trees easily.18. 听力题：My favorite subject is _____ (math/science).19. 听力题：A ____ is a gentle giant that can be very friendly.20. 听力题：Planets are classified as terrestrial or ______.21. 填空题：A ____(green certification) recognizes sustainable practices.22. 填空题：The capital of the Gambia is ________ (班珠尔).23. 听力题：The __________ is a region known for its unique languages.24. 填空题：My dad enjoys cooking on the ____.25. 选择题：Which animal is known for its ability to swim fast?A. DogB. DolphinC. CatD. Elephant答案:B26. 听力题：A prism can separate light into different ______.27. 填空题：Many plants are _____ (可食用) and nutritious.28. 填空题：I enjoy _______ (喝果汁) in the summer.29. 选择题：What is the opposite of 'fast'?A. QuickB. SlowC. SpeedyD. Rapid30. 填空题：The ________ (机场) is busy with travelers.31. 选择题：What do bees make?A. MilkB. HoneyC. ButterD. Jam答案:B32. 听力题：I like to _____ in the garden. (play)33. 听力题：Matter is anything that has ______.34. 听力题：The chemical formula for beryllium oxide is ______.35. 选择题：What is the opposite of 'hot'?'热'的反义词是什么？A. ColdB. WarmC. CoolD. Boiling答案: A36. 选择题：What is the main ingredient in a salad?a. Meatb. Vegetablesc. Fruitd. Bread答案:B37. 听力题：The Titanic sank on its maiden _______.38. 听力题：Some _______ are grown for their beauty.What is the name of the popular game where you try to guess words based on clues?A. PictionaryB. CharadesC. TabooD. Scattergories答案: A40. 选择题：What do you call a young female goat?A. KidB. CalfC. LambD. Pup答案: A41. 填空题：The ________ is small and cute.42. 填空题：The ________ (历史遗迹) tell stories of the past.43. 填空题：I saw a __________ form in the sky before the storm. (乌云)44. 填空题：I hear birds singing when it’s ______ (晴天).45. 选择题：What is the capital city of Russia?A. MoscowB. St. PetersburgC. KazanD. Novosibirsk答案: A46. 选择题：What do we call a computer program that helps us to create documents?A. BrowserB. Word processorC. SpreadsheetD. Game答案:BA ______ (多样的生态系统) promotes resilience.48. 填空题：My favorite number is ______.49. 填空题：The __________ (地貌) shapes the landscape.50. 听力题：Organic chemistry is the study of ______ compounds.51. 听力题：Some _______ can be climbing or trailing.52. 选择题：Which item is used to tell time?A. CalendarB. ClockC. MapD. Book答案：B53. 听力题：The park is ___ (full/empty) of children.54. 听力题：__________ is the process of separating a mixture into its components.55. 听力题：The process of ______ can lead to the discovery of fossils.56. 填空题：A _____ (狒狒) can be quite mischievous.57. 选择题：What is the primary function of the lungs?A. To pump bloodB. To digest foodC. To absorb oxygenD. To filter waste答案: C58. 填空题：The owl has _______ (大眼睛) for night vision.Electric fields can exert ______ (forces) on charged particles.60. 填空题：The ________ (养分) in the soil is important for growth.61. 听力题：She likes to wear ________ shoes.62. 听力题：They are going to ________ a concert.63. 填空题：The ancient Greeks believed in many _____ and myths.64. 填空题：My brother loves to __________ (参加) sports tournaments.65. 填空题：A __________ (生态旅游) promotes awareness of environmental issues.66. 选择题：What is the capital of Vietnam?A. Ho Chi Minh CityB. HanoiC. Da NangD. Can Tho答案:B. Hanoi67. 听力题：The wind is ______ (blowing) gently today.68. 填空题：A horse is used for riding and ________________ (工作).69. 选择题：How many months are there in a year?A. TenB. TwelveC. ElevenD. Nine70. 填空题：The musician plays the _____ (小号) in the band.What do you call a story with animals that talk?A. Fairy taleB. FableC. BiographyD. Novel72. 选择题：What is the process of changing from liquid to gas called?A. FreezingB. MeltingC. EvaporationD. Condensation答案: C73. 选择题：How do you say "再见" in English?A. HelloB. GoodbyeC. PleaseD. Thank you74. 听力题：This is my best ____ (friend). We go to school together.75. 选择题：How many days are in a week?A. FiveB. SixC. SevenD. Eight76. 填空题：The ______ (植物的生长速度) can vary based on conditions.77. 填空题：On a sunny day, I decided to visit the ______ (1) with my family. We packed a picnic basket filled with sandwiches, fruits, and drinks. When we arrived, the park was filled with ______ (2) enjoying the beautiful weather. My little brother ran stra78. 填空题：The scientist discovered a new _____ (物种).79. 填空题：I have a new _______ (背包).We are having a ___. (picnic) this weekend.81. 填空题：The goldfish can live for several _________ (年).82. 听力题：The ______ teaches us about different countries.83. 选择题：What is the capital of Australia?A. SydneyB. CanberraC. MelbourneD. Brisbane答案: B84. 听力题：Birds have ______ to help them fly.85. 填空题：My __________ (玩具名) is very __________ (形容词) to play with.86. 填空题：I enjoy reading ______ (故事) before going to sleep.87. 填空题：My family loves to __________ on holiday. (度假)88. 选择题：How many sides does a pentagon have?A. 4B. 5C. 6D. 7答案: B89. 听力题：He is _____ (running) very fast.90. 选择题：What do we call the process of a caterpillar turning into a butterfly?A. EvolutionB. MetamorphosisC. DevelopmentD. Transformation答案:B91. 填空题：Ancient Egyptians believed in many ________.92. 听力题：The first man to reach the South Pole was _______ Amundsen.93. 填空题：My teacher encouraged us to create our own ________ (漫画). I drew a funny ________ (角色).94. 选择题：Which one is a popular sport?A. SwimmingB. EatingC. SleepingD. Writing95. 选择题：What do you call a person who writes music?A. ComposerB. MusicianC. LyricistD. All of the above答案:D96. 听力题：Vinegar is an example of an _______.97. 听力题：Reactions that happen quickly release more ______.98. 听力题：The first human to fly in space was _______ Gagarin.99. 听力题：I like to play ______ (video games) on weekends.100. 填空题：A _______ (蜥蜴) can be found on warm rocks.。

小学上册英语第四单元真题(含答案)考试时间：100分钟（总分:110）B卷一、综合题(共计100题共100分)1. 听力题：The teacher gives us _____ (homework/tests).2. 选择题：What do you call a young crocodile?A. HatchlingB. PupC. CalfD. Kit3. 选择题：What do we call the process of converting a liquid into a solid?A. MeltingB. FreezingC. EvaporationD. Solidification4. 填空题：The raccoon is known for its ______ (面具).5. resource management) ensures sustainability. 填空题：The ____6. 填空题：The _______ (American Revolution) led to the independence of the thirteen colonies.7. 填空题：The ancient Egyptians wrote on _______ made from papyrus. (纸)8. 填空题：The __________ (古巴导弹危机) was a significant event in the Cold War.What is 7 + 5?A. 10B. 11C. 12D. 13答案:C10. 填空题：The _____ (linden) tree has fragrant flowers.11. 听力题：The city of Port Moresby is the capital of _______.12. 填空题：We visit the ______ (文化中心) for events.13. 选择题：What is the name of the fairy tale character who kissed a frog?A. Snow WhiteB. Sleeping BeautyC. The Princess and the FrogD. Cinderella14. 填空题：My brother has a toy ______ (赛车). He loves to race it on the ______ (地板).15. 填空题：Chromatography is a method used to separate _______. (色素)16. horizon) appears differently at sea compared to land. 填空题：The ____17. 填空题：I dream of becoming a ________ (医生) when I grow up. I want to help ________ (病人).18. ssance artist Michelangelo painted the ceiling of the _______. (西斯廷教堂) 填空题：The Rena19. 填空题：My dog loves to chase ______ (球) in the yard.20. 填空题：I saw a ________ running across the road.A chemical reaction requires a change in ______.22. 听力题：The Great Wall of China was built to protect against _______.23. 填空题：A ________ (湿地) is important for wildlife.24. 选择题：What do we call the highest point of a mountain?A. SummitB. BaseC. FootD. Ridge答案:A25. (75) is famous for its beautiful beaches. 填空题：The ____26. 填空题：The painter, ______ (画家), uses bright colors in her artwork.27. 选择题：What do we call the person who writes books?A. ArtistB. AuthorC. TeacherD. Scientist答案:B28. trial Revolution began in __________. (英国) 填空题：The Indu29. 填空题：The rabbit's _______ (嗅觉) helps it find food.30. 填空题：The __________ is a large area of frozen land found in Antarctica. (南极洲)31. 听力题：I see a _____ (fox) in the woods.32. 填空题：The ______ (老虎) has stripes that help it blend in.What do we call a scientist who studies the structure of the Earth?A. GeologistB. ArchaeologistC. PaleontologistD. Environmental Scientist34. 选择题：What do you call the sound made by a bell?A. DingB. BongC. RingD. Chime答案: D35. 听力题：My sister enjoys reading ____ (biographies).36. 听力题：An __________ is a reaction that releases light or heat.37. 听力题：Flowers need ______ to grow.38. 听力题：We have ___ (history/math) class today.39. 填空题：The _______ (The Age of Exploration) led to European colonization of the Americas.40. 选择题：What is the name of the fairy in Peter Pan?A. CinderellaB. TinkerbellC. Snow WhiteD. Ariel答案: B41. 听力题：__________ are used in the production of rubber.42. 听力题：The pH scale ranges from to _____.43. 听力题：The cake is very ___. (delicious)Kinetic energy is the energy of ______.45. 选择题：What do we breathe?A. WaterB. AirC. FoodD. Light46. 听力题：A strong electrolyte dissociates completely in ______.47. 听力题：The capital of Saint Vincent is __________.48. 听力题：The dog is _____ (running/sitting) in the yard.49. 选择题：What do we call the seasons that occur after summer?A. WinterB. SpringC. FallD. Autumn答案: C50. 填空题：The owl has excellent _______ (夜间视力).51. 填空题：The __________ (农场) is home to many crops.52. 选择题：What do we call a person who flies an airplane?A. PilotB. EngineerC. MechanicD. Navigator答案:A53. 选择题：What do we call the act of improving relationships?A. ReconciliationB. HealingC. MendingD. All of the Above答案：D54. 听力题：I need to _______ (wash) my hands.55. 听力题：We celebrate ______ (Christmas) in December.56. 听力填空题：I believe in the power of dreams. If we work hard, we can turn our dreams into reality. My dream is to __________ and make a difference in the world.57. 听力题：The ________ (scarf) is warm and cozy.58. 听力题：He is my _____ (teacher).59. 填空题：_____ (土壤) quality affects plant growth.60. 听力题：The capital of Thailand is __________.61. 听力题：The chemical formula for benzene is ______.62. 填空题：My dad helps me with _______ (作业).63. 听力题：The __________ is a region known for its mountains and valleys.64. 听力题：The _____ (椅子) is broken.65. 听力题：Emma is a ______. She likes to read stories.66. 选择题：What is the name of the color found between blue and yellow?A. PurpleB. GreenC. OrangeD. Red答案: B67. 听力题：The ancient Greeks created ________ to teach philosophy.68. 选择题：Which insect is known for making silk?A. AntB. ButterflyC. SilkwormD. Beetle答案：C69. 听力题：The ____ is a small mammal that loves to scamper around.70. 听力题：The fish are swimming in the ___ (tank/aquarium).71. 听力题：The stars are ___ (shimmering) tonight.72. 听力题：The _____ (parrot) can talk.73. 听力题：I like to ________ new things.74. 填空题：My favorite color is ________ (蓝色) because it is calming.75. 听力题：The element with the symbol W is __________.76. 听力题：My dad is very ________.77. 听力题：The ____ has a unique tail and enjoys climbing.78. 填空题：The __________ (探险活动) is thrilling and educational.79. 填空题：My friend is very __________ (有天赋).My pet rabbit loves to eat fresh ______ (胡萝卜).81. 填空题：Wildflowers grow __________ (自然) in the fields.82. 选择题：What do we call the largest organ in the human body?A. HeartB. SkinC. LiverD. Brain答案: B83. 填空题：The doctor gives _____ (建议) about staying healthy.84. 选择题：What do you call a young female cow?A. CalfB. HeiferC. KidD. Lamb答案: B85. 听力题：A reaction that occurs in the presence of heat is called a ______ reaction.86. 选择题：Which insect is known for its ability to build a hive?A. AntB. BeeC. ButterflyD. Mosquito答案:B87. 填空题：In 1492, Christopher Columbus sailed the ocean _______. (蓝)88. 填空题：A _____ (食用植物) can be grown at home easily.89. 听力题：The ____ is a small animal that hops around in the garden.We will have ______ for dessert. (cake)91. 选择题：What is the term for the process of water vapor turning into liquid water?A. EvaporationB. CondensationC. PrecipitationD. Sublimation答案: B92. 填空题：Plants can create ______ (栖息地) for wildlife.93. 填空题：My grandma is a wonderful __________ (谈话者) who shares stories.94. 听力题：The _______ can help improve your mood.95. 选择题：What is the name of the famous ancient structure located in Greece?A. ParthenonB. ColosseumC. PyramidsD. Stonehenge答案：A96. 选择题：What do you call a baby shark?A. PupB. FryC. CalfD. Kit答案: A97. 填空题：My brother loves to play . (我哥哥喜欢玩。

河北省沧州市2024-2025学年高三上学期10月月考英语试题一、阅读理解Below is the general information that can help you if you want to visit the Eiffel Tower.Attendance throughout the dayAttendance throughout the weekSaturdays and Sundays are the busiest days of the week and attendance is usually lowest on Tuesdays, Wednesday s and Thursdays.Avoid lines at the cash registerTo beat the queues, buy your tickets from our online ticket office, especially if you’re heading to the top of the Tower. By buying time-stamped e-tickets, you’ll save time at the Tower! You can book your visit up to two months in advance, especially for July and August, when the Eiffel Tower is at its busiest.Electronic tickets for the Eiffel Tower are on sale 60 days in advance. They may be available the day of your visit, up to 3 hours prior to your visiting time.Our online ticket office is where you can find the best prices for our e-tickets to the top or the 2nd floor.How much does it cost to visit the Eiffel Tower?The adult price is €20, which applies to adults 25 years and over. There are discount rates for young people (12—24 years old: 20% off) and children (4—11 years old: 40% off). Admission is free for children under 4 years old.1．Which time may be less crowded on a visit to the Eiffel Tower?A．At 9 PM on Thursday.B．At 11 AM on Friday.C．At 10 AM on Saturday.D．At 7 PM on Sunday.2．What is advised if you want to reach the top of the Tower?A．Purchase cheap tickets on the 2nd floor.B．Buy time-stamped e-tickets in advance.C．Visit the Eiffel Tower in summer months.D．Save time by waiting at the cash register. 3．How much is the admission for a couple and their 9-year-old son?A．€20.B．€32.C．€48.D．€52.Twenty-five-year-old Ana Victoria Espino in Mexico has become the world’s first lawyer with Down syndrome (唐氏综合征). It has made history in Mexico. Having studied in the institution’s law school for five years, she received her law degree from Universidad Autonoma de Zacatecas.In Mexico, there is no bar exam—getting a law degree is enough to be a lawyer. However, rather than defending people in the court of law, Espino aims to use her legal knowledge to improve conditions for people with disabilities.For Espino, becoming a lawyer was a long-time dream. Espino grew up with a strong family network including her parents and three siblings (兄弟姐妹), which has been the foundation of her educational and professional careers. In the classroom, she also received helpful accommodations to enter high school like being able to study independently for the entrance exam.After graduating, Espino applied for a university and stood out in the admission exam. However, the school’s headmaster refused her application despite her excellent grades in the exam, because the school lacked the conditions for a person with Down syndrome.Moved by her determined spirit, a professor offered to help Espino. Throughout her five years of college, the teacher accompanied Espino to all of her classes, helped her study, and prepared her for exams.Espino’s career as an advocate for people with disabilities predates (早于) her pursuing a degree. She often shares her story to bring light to people with disabilities. She is also a talented artist, holding several exhibitions.As for the future, Espino has a very clear image of what she wants to achieve. She said, “I am fanatical about the law and I want to ensure all people who live with a disability can occupy decision-making spaces to contribute to improving their conditions.”4．What does Espino expect to do in the future?A．To give a hand to the disabled.B．To cure people of Down syndrome.C．To attach importance to human’s equal rights.D．To inspire the disabled to learn legal knowledge.5．What happened to Espino when applying for a university at first?A．She moved the headmaster.B．She lost her parents’ support.C．She was turned down by the school.D．She did badly in the admission exam. 6．What does the underlined word “fanatical” in the last paragraph probably mean?A．Uncertain.B．Annoyed.C．Passionate.D．Curious. 7．Which words can best describe Espino?A．Humble and wise.B．Generous and brave.C．Humorous and hard-working.D．Strong-willed and caring.In 1973, the National Hurricane Center introduced the Saffir-Simpson scale (created by Herbert Saffir and Robert Simpson), a five-category rating system that classified hurricanes by wind intensity. At the bottom of the scale was Category 1, for storms with sustained winds of 74 to 95 mph. At the top was Category 5, for disasters with winds of 157 mph or more.In the half-century since the scale first appeared, land and ocean temperatures have steadily risen as a result of greenhouse gas emissions (排放). Hurricanes have become more intense, with stronger winds and heavier rainfall.With disastrous storms regularly blowing past 157 mph, some scientists argue, the Saffir-Simpson scale no longer conveys the threat the biggest hurricanes present. The strongest hurricane recorded over the Pacific Ocean has a sustained wind of 215 mph. “That’s faster than a racing car. It’s a new and dangerous world,” said Michael F. Wehner, a co-author of a Category 6 paper.“The Saffir-Simpson scale is not all that good for warning the public of the danger of a storm,” Wehner said. The category scale measures only sustained wind speeds, which is just one of the threats a major storm presents. The rest are storm surges (风暴潮), flooding and big tides.But the National Hurricane Center has no plans to introduce a Category 6, primarily because it is already trying “to not emphasize the scale very much,” said Brennan, the National Hurricane Center director. Other meteorologists said that’s the right call. “I don’t see the value init at this time.”Simplistic as they are, Herbert Saffir and Robert Simpson’s categories are the first things many people think of when they try to grasp the scale of a storm. In that sense, the scale’s persistence (持续存在) over the years helps people understand how much the climate has changed since its introduction. “What the Saffir-Simpson scale is good for is quantifying, showing that the most intense storms are becoming more intense because of climate change,” Wehner said. “It’s not like it used to be.”8．Why does Wehner suggest a new rating system?A．To describe more intense hurricanes.B．To control greenhouse gas emissions.C．To avoid the threat of hurricanes timely.D．To better understand the nature of hurricanes.9．What does Brennan think of the Category 6?A．Primary.B．Needless.C．Valuable.D．Incomplete. 10．What does the last paragraph mainly tell us about the Saffir-Simpson scale?A．Its simplicity.B．Its long history.C．Its positive role.D．Its great change. 11．What can be the best title for this text?A．A New Rating System Is ApprovedB．Climate Change Caused More HurricanesC．Extreme Weather Has Become a New NormD．A Bigger Number Might Be Needed for HurricanesThe small hobby of chocolate is becoming a more costly one. Rapidly increasing prices for cocoa beans recently hit a record $12,000 a tonne: roughly four times last year’s price. Many think they will go higher. That may put small specialist producers out of business. Yet it is bringing little reward to struggling growers.The immediate cause is a bad harvest in West Africa—which produces 70% of the world’s beans—reflecting El Niño-linked weather patterns and disease. Major processing plants in Ghana and Ivory Coast, the main growers, have stopped or reduced operations because they cannot afford the beans. But underlying the crisis are longer-term issues including the climate crisis and theinability of farmers to invest in production due to their low incomes.Many West African growers are being forced out of the business after years of punishingly low returns for their work and—as trees come to the end of their life cycle—often selling land to gold miners, resulting in severe environmental degradation (恶化). Latin American farmers are rushing to plant cocoa due to the higher prices, abandoning other crops and deforesting new areas. But the likelihood, if production booms and the system does not change, is that by the time their new trees bear fruit, prices may be falling again.As serious as the situation looks, the attention demanded by the rocketing price of cocoa, and the introduction of EU Deforestation Regulation offer an opportunity. Faced with global heating, increasing conflict and energy price instability, depending on the free market is a poor bet. Treating food issues as financial instruments hurts farmers, destroys forests and worsens the instability of supply.The solution in this case is a commitment to stable minimum prices for cocoa farmers and long-term contracts. This would help to lift growers out of poverty and, in doing so, tackle other problems. Sustainable production is essential, and will even benefit consumers in the long run. It can’t be achieved by letting the free market run its course.12．What might be the consequence of rising cocoa prices?A．Some small producers will fail.B．Cocoa farmers will benefit greatly.C．Fewer people will eat chocolate.D．Cocoa production will increase.13．What will happen if more Latin American farmers plant cocoa?A．Other crops will boost production.B．Cocoa prices will go down.C．The environment will be improved.D．Old cocoa trees will be abandoned. 14．What is the author’s attitude towards the free market approach to cocoa problems?A．Defensive.B．Concerned.C．Optimistic.D．Indifferent. 15．What does the author suggest in order to solve the coco a problem?A．Allowing the free market to work.B．Giving cocoa farmers more freedom.C．Helping cocoa growers out of poverty.D．Promising a steady guaranteed price.Want your flower garden to look like those at the Botanical Garden? Here are some tips.How do you arrange a flower garden?Like most things, your best bet is to keep it simple. Use large blocks of color in your home flower garden. Keep in mind that annuals require care and even the hardiest need to be watered and fertilized. 16How often do you need to water a flower garden?Water your flower garden immediately after planting annuals, and keep an eye on them for the next week or so. 17 If it rains, you may still need to water them because sometimes it doesn’t soak (浸透) the ground. If you’re unsure, stick your finger in the soil at the base of the plant, and feel if it is wet or dry.18Visit your local garden store that sells well-grown annuals that are in either flats or 4-inch pots. Most of the time the vigorous (茁壮的) plants that do well are in 4-inch pots. Growing from seed can be fun in the back of the garden, but when you are really counting on color, buy plants.How do you prepare the soil before planting flowers?19 You may have to apply some efforts to get the dirt in good enough shape to plant annuals. The most important tip is to dig up your soil with a shovel (铲) to make sure it’s loose and soft. Try for 6 to 8 inches deep. 20 If you have to chip away at the soil to plant your flowers, you are in for an uphill battle in which you will not win.A．What flowers are best for a flower garden?B．So your flower bed should be near water outlets.C．If you can’t dig with your hands, the soil is not ready.D．Once the annuals are established, water two times a week.E．Should you plant seeds or use potted plants for a flower garden?F．Soil preparation starts with knowing the soil type that’s native to your area.G．If you add organic matter occasionally, your garden should be in good condition.二、完形填空Going into my Ph.D．program, I loved to communicate science to the public. But 21 consumed most of my time. I often worked past nightfall, and my weekends were 22 absorbed by preparing experiments, gathering data, or catching up on the seemingly 23scientific papers.I desperately needed a 24 , so I jumped at an opportunity to spend a weekend with friends. When they talked about the latest books they’d 25 , I only recalled every detail of the papers piling up in the lab, yet I couldn’t 26 the last book I had read for fun. So I found myself mostly talking about my research. As I struggled to 27 its broader association in life, I noticed the enthusiasm in my voice faded. “Is my Ph.D．28 my love for science?” I thought.I decided to read for fun. My brother recommended a science fiction book. I was soon29 by the scientifically plausible (可信的) technologies in it. It was 30 to think about science in a new way. I began to love it.Later, I was 31 to give a talk about the science behind science fiction. When the day came to 32 , I felt nervous. But after I finished, I was surrounded by some 33 audience. It suddenly occurred to me that this was my 34 back to science communication. Since then, I have given 20 talks, exploring 35 like genetic (基因的) engineering, and brain-machine interfaces.21．A．housework B．reading C．research D．volunteering 22．A．initially B．particularly C．largely D．randomly 23．A．abstract B．endless C．valueless D．reasonable 24．A．chance B．rest C．suggestion D．challenge 25．A．written B．checked C．exchanged D．consumed 26．A．share B．remember C．find D．refuse 27．A．distinguish B．understand C．seek D．express 28．A．killing B．giving C．discovering D．boosting 29．A．carried through B．blown away C．set apart D．taken out 30．A．refreshing B．necessary C．puzzling D．strange 31．A．funded B．instructed C．inspired D．invited 32．A．present B．perform C．exhibit D．leave 33．A．energetic B．confident C．excited D．humorous 34．A．path B．conclusion C．fault D．determination 35．A．details B．methods C．shifts D．concepts三、语法填空阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

小学上册英语第二单元真题试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.Did you see a _______ (小蜈蚣) crawling on the ground?2. A _______ can be a climbing plant.3.What do you call a collection of stars?A. GalaxyB. PlanetC. Solar systemD. Nebula4.An atom that gains electrons becomes a _____ ion.5.The chemical formula for iron(III) sulfate is _____.6.What color are ripe bananas?A. GreenB. RedC. YellowD. BlueC7.The sun is ______ behind the clouds. (peeking)8.What is the capital of Turkey?A. IstanbulB. AnkaraC. IzmirD. Antalya9. Pyramid of Giza is one of the Seven Wonders of the _____. The Grea10.We go to school by ________ (自行车).11.Fungi are not _____ (植物) but they grow in soil.12.What is the name of the ocean that is the largest?A. AtlanticB. IndianC. ArcticD. Pacific13.I enjoy going to the ______ (咖啡馆) with my friends to chat and relax. It’s a cozy place.14.Circuits can be series or ______.15.I love to eat ______ (冰淇淋) in the summer. My favorite flavor is ______ (巧克力).16.The first telephone was invented by ________ Bell.17.What is the primary color of the sky on a clear day?A. PurpleB. GreenC. BlueD. Yellow18.The ancient Greeks made significant contributions to ________.19.Temperature is measured in degrees ______.20.What do you call the time before noon?A. MidnightB. MorningC. AfternoonD. EveningB21. A ________ (树枝) can break if it is too heavy.22.How many legs does a bee have?A. 4B. 6C. 8D. 10B23.The puppy is _______ (很可爱).24.What is the capital of the Philippines?A. ManilaB. CebuC. DavaoD. Iloilo25.His favorite animal is a ________.26.My favorite animal is a ________ (小狗).27.I want to _____ (go/stay) at home.28.The armadillo rolls into a ____.29.My toy robot can dance and ______.30.The sky is _______ (乌云密布).31.The milk is ___. (cold)32.She has a ___ (nice) dress.33.How many legs does a spider have?A. 6B. 8C. 10D. 1234. A ______ (植物病害) can harm crops.35. A _______ (小鱼鹰) dives into the water to catch fish.36.The process of burning wood produces _____ and ash.37.What is the name of the famous explorer who discovered America?A. Christopher ColumbusB. Ferdinand MagellanC. Marco PoloD. Vasco da GamaA Christopher Columbus38.I love to read ______ books at the library.39.What do we call a large natural stream of water?A. RiverB. CreekC. StreamD. BrookA River40.What is the name of the famous bear in the children's book series by A.A. Milne?A. Paddington BearB. Winnie-the-PoohC. Yogi BearD. BalooB41.I love to bake ________ (面包) with my grandmother.42.Which of these is a common pet?A. CowB. DogC. HorseD. Sheep43.Many galaxies are moving away from us, suggesting the universe is ______.44.What do we call the act of traveling to a foreign country for leisure?A. VacationingB. TouringC. TravelingD. ExploringA45.The ancient Greeks made significant contributions to _______.46.What is the name of the famous ancient city in Jordan?A. PetraB. BabylonC. UrD. NinevehA47.The ______ (植物的生长方式) is influenced by many factors.48.They are ___ (walking/running) in the park.49. A parrot has bright ______ (羽毛).50.What is the name of the first spacecraft to land on Mars?A. Viking 1B. SpiritC. OpportunityD. Curiosity51.My favorite toy is a ________ (玩具名). It makes me feel very ________ (形容词) when I play with it. Every time I take it out, I can’t help but ________ (动词) with joy.52.My favorite place is the ______.53.The movie is very ________.54.What is the freezing point of water?A. 0 degrees CelsiusB. 100 degrees CelsiusC. 32 degrees FahrenheitD. Both A and CD55.The ______ (生态系统) includes many interconnected parts.56.Coral reefs are made up of tiny ______.57.What is the name of the large body of saltwater?A. LakeB. RiverC. OceanD. PondC58.My mom loves __________ (探索新的思想).anic compounds contain _____ (carbon).60.I can ______ (dance) with my friends.61.My dad works _____ (hard/easy) every day.62.I enjoy making ________ (手工艺品) for my friends.63.__________ are found on the right side of the periodic table.64.What is 5 + 3?A. 6B. 7C. 8D. 965.What do you call a person who studies insects?A. BiologistB. EntomologistC. ZoologistD. BotanistB66.What do you call the place where you can buy groceries?A. StoreB. MallC. SupermarketD. MarketC67.My favorite game is _______.68.听录音判断，与图片内容相符的打√，不符的打x。