A Test of the Critical Period Hypothesis for Second Language Acquisition

高一英语科学发现词汇应用高级单选题40题1. In the process of scientific research, a(n) ____ is often put forward first, which is a proposed explanation for a phenomenon.A. experimentB. hypothesisC. observationD. conclusion答案：B。

解析：本题考查科学发现相关词汇的辨析。

“hypothesis”意为假设，在科学研究中通常首先提出一个假设来解释某种现象，这是科学研究的常见步骤。

“experiment”是实验，是用来验证假设的手段，而非首先提出的内容。

“observation”是观察，虽然观察也是研究的一部分，但不是这种对现象提出解释的概念。

“conclusion”是结论，是在经过一系列研究之后得出的结果，不是一开始就提出的。

2. Scientists made a careful ____ of the strange phenomenon before they started their research.A. experimentB. hypothesisC. observationD. discovery答案：C。

解析：这里考查词汇的语境运用。

“observation”表示观察，科学家在开始研究之前会对奇怪的现象进行仔细观察，这是符合逻辑的。

“experiment”是进行实验，在还未开始研究时不会先进行实验。

“hypothesis”是假设，此时还未到提出假设的阶段。

“discovery”是发现，这里强调的是对现象的观察过程，而不是发现这个结果。

3. The ____ they designed was very complicated but it could test their hypothesis effectively.A. experimentB. observationC. conclusionD. theory答案：A。

Focusing on ReadingTask 11.G2. E3. C4. F5. A6. D7.J8. B9.L10.H 11. N 12. M 13. Q 14.K 15. I 16.R 17.O 18.PTask 21)The reasons are as follows”Firstly, students sometimes view academic dishonesty as a normal incidence and something ordinary. There are many reasons that they use to justify their cheating.Secondly, new techniques of cheating have been developed, including the use of high-tech tools, although the old ones are still dominant on campus, which makes it even more difficult for the faculty to identify.Thirdly, it is a common view to equate grades with the value of the student. Furthermore, grades are used to predict one’s future success. So some students tend to practice academic dishonesty with the aim of getting higher grades.Fourthly, little is known about the degree of academic dishonesty and no methods are devised to combat the problem. Besides, there are no strategies for deterring academic dishonesty for the faculty.Fifthly, honor codes are essential to reducing the level of cheating in colleges and should be established. However, their importance has been neglected.Last but not least, academic dishonesty is no longer a task of classroom management that can well be remedied by a single faulty with teaching responsibility. Administrators and professional organizations are expected to work together to maintain a healthy learning environment with a high level of trust between the faculty and the administration.2)Old techniques include bringing notes to class and having information written on water bottles,pens and gum wrappers. New techniques of cheating include using cell phones to get the information, communicate with others outside the exam room to obtain answers and searching answers on the web during an exam.Other forms include copying test responses from a classmate, taking exams for other people, failure to cite other people’s work, and purchasing research papers and presenting them as his/her work. Also actions such as breaking into the office or teachers files to access the test or answer key, sabotaging peers ongoing work or gaining illegal access to school computers to change official grades are all forms of academic dishonesty. (B)3)There are many reasons that students use to justify cheating: lack of time, poverty, uncaringinstructors, laziness, peer pressure, poor rile models, fear of failure and technology that has allowed cheating to be done easily. (C)Besides, research shows that a common view equates grades with the value of the student.Secondly, grades are used to predict one’s future success. This may cause the students to practice academic dishonesty.4)Studies show that honor codes were essential to reducing the level of cheating in colleges.Honor codes would be more successful when they were combined with a climate that emphasized the importance of academic integrity and an honor system that allowed for strong student involvement in the enforcement of academic integrity initiatives. Therefore, the administration should strive in the creation of the campus environment, seek the full support of all the college constituents, and ensure the implementation of the honor codes at theinstitution. (N)5)Academic fraternity means “all the people who work in academia.”It can stress integrity as a core institutional value that will shape the students’academic success.Task 31. a2. j3. W4. m5. k6. o7. v8. x9.n 10.b 11. u 12.y 13.d14. i 15. f 16. z 17. t 18.p 19. S 20. q 21. e 22. g 23. c 24. h 25. l 26. rTask 51)Another kind of academic dishonesty happens sometimes among researchers when they yieldto the temptation of making a series of great discoveries. So they invent false information to deceive others, and then publish them.2)Bouville(2010) held that the major reason for the students to avoid academic dishonesty wasto obey the rules and escape punishment. Cheaters may get high grades which they do not deserve, and this unfair advantage will tempt them to continue with this fraudulent behaviour.3)Third, in each department there should be experienced faculty members, acting as academicintegrity chairmen, who are responsible for contacting and offering help to their fellow colleagues. Lastly, for faculty members who have tackled the cases of academic dishonesty well, public thanks and admiration should be given to them for what they have done.Task 6Main idea: Students developed new techniques of cheating, while the old ones are still dominant on campus.Task 7In the area of education, academic dishonesty is a chronic problem. Students have developed new techniques of cheating, while the old ones are still dominant on campus. Cheaters follow dishonest practices because of many reasons. Prevention of academic dishonesty demands joint efforts from students, teachers and administrators, of which the students’ contribution is vital for they are the ones to be subjected to the penalties. For the teachers, they can adopt four strategies to maintain academic integrity and meanwhile make efforts to motivate the students. For the administrators, they should strive in the creation of a healthy academic climate and ensure the implementation of the honor codes.Task 8(omitted)Task 9(omitted)Task 10Academic DishonestyAcademic dishonesty occurs when a student uses or attempts to use unauthorized information in the taking of an exam; or submits as his or her own work themes, reports, drawings, laboratory notes, or other products prepared by another person; or knowingly assists another student in such acts or plagiarism. Such behavior is abhorrent to the university, and students found responsible for academic dishonesty face expulsion, suspension, conduct probation, or reprimand. Instances of academic dishonesty ultimately affect all students and the entire university community by degrading the value of diplomas when some are obtained dishonestly, and by lowering the grades of students working honestly.Examples of specific acts of academic dishonesty include but are not limited to:a) Obtaining unauthorized information. Information is obtained dishonestly, for example, bycopying graded homework assignments from another student, by working with another student on a take-home test or homework when not specifically permitted to do so by the instructor, or by looking at your notes or other written work during an examination when not specifically permitted to do so.b) Tendering of information. Students may not give or sell their work to another person who plans to submit it as his or her own. This includes giving their work to another student to be copied, giving someone answers to exam questions during the exam, taking an exam and discussing its contents with students who will be taking the same exam, or giving or selling a term paper to another student.c) Misrepresentation. Students misrepresent their work by handing in the work of someone else. The following are examples: purchasing a paper from a term paper service; reproducing another person’s paper (even with modifications) and submitting it as their own; having another studentdo their computer program or having someone else take their exam.d) Bribery. Offering money or any item or service to a faculty member or any other person to gain academic advantage for yourself or another is dishonest.e) Plagiarism. Unacknowledged use of the information, ideas, or phrasing of other writers is an offense comparable with theft and fraud, and it is so recognized by the copyright and patent laws. Literary offenses of this kind are known as plagiarism.One is responsible for plagiarism when: the exact words of another writer are used without using quotation marks and indicating the source of the words; the words of another are summarized or paraphrased without giving the credit that is due; the ideas from another writer are borrowed without properly documenting their source.Acknowledging the sources of borrowed material is a simple, straightforward procedure that will strengthen the paper and assure the integrity of the wri ter. The Student’s Guide to English 104 —105, provides guidelines to aid students in documenting material borrowed from other sources, as does almost every handbook on writing style.Academic dishonesty is considered to be a violation of the behavior expected of a student in an academic setting as well as a student conduct violation. A student found responsible for academic dishonesty or academic misconduct is therefore subject to the appropriate academic penalty; to be determined by the instructor of the course, as well as sanctions under the university Student Disciplinary Regulations.If an instructor believes that a student has behaved dishonestly in a course, the following steps are to be followed:1. The instructor should confront the student with the charge of dishonesty and arrange a meetingwith the student to discuss the charge and to hear the student’s explanation.2. If the student admits responsibility for academic misconduct, the instructor shall inform the student (a) of the grade on the work in which the dishonesty occurred, and (b) how this incident will affect subsequent evaluation and the final grade. Because academic dishonesty is also a student conduct violation under Section 4.2.1 of the Student Disciplinary Regulations, the instructor must report the incident in writing to the Dean of Students.After investigating the incident and discussing it with the instructor, the Dean of Students, or his/her designee, will meet with the student and depending on the severity of the offense as well as on the student’s past conduct record, may handle the matter through an administrative hearing or schedule a hearing before the All University Judiciary (AUJ).This hearing, conducted according to the procedures outlined in the Student Disciplinary Regulations, is to determine the disciplinary action to be taken. In any case, the student’s academic adviser will be informed of the incident but may not insert any record of it in the student’s academic file.3. If the student claims to be not responsible for the alleged violation of academic misconduct, the instructor may not assign the student a grade for the work in question until the question of responsibility is resolved, unless circumstances require that an interim grade be assigned. The instructor shall consult with his or her department chair and report the incident in writing to the Dean of Students.The Dean of Students will refer the case to the Office of Judicial Affairs for investigation. After reviewing the report and completing an investigation, the Office of Judicial Affairs will file aformal complaint against the student if it is determined that there is cause to believe academic misconduct occurred. The case may be adjudicated through an administrative hearing or referred to a hearing before the All University Judiciary (AUJ) depending on the nature and severity of the violation as set forth in the Student Disciplinary Regulations.If the case is referred to the AUJ both the student and instructor will be invited to attend an AUJ hearing and present pertinent information. If the Administrative Hearing Off icer (in a minor case) or the AUJ (in a major case) finds the student responsible for the charge of academic misconduct, the instructor will inform the student (a) of the grade on the work in which the dishonesty occurred, and (b) how this incident will affect subsequent evaluation and the final grade. The Administrative Hearing Officer or AUJ will determine the appropriate disciplinary action with respect to the nature of the violation.If the Administrative Hearing Officer or AUJ finds the student “not responsible” for academic misconduct, the instructor will grade the student accordingly on the work in question and the student’s grade in the course will not be adversely affected. If th e student is found responsible the student’s adviser will be informed of the decision but shall not insert any record of the action in the student’s academic file.4. If a student either admits dishonest behavior or is found responsible for academic misconduct by the AUJ, the Off ice of Judicial Affairs (OJA) or AUJ may impose any of the following sanctions:a) Disciplinary Reprimand: An official written notice to the student that his/her conduct is in violation of university rules and regulations.b) Conduct Probation: A more severe sanction than a disciplinary reprimand, to include a period of review and observation during which the student must demonstrate the ability to comply with university rules, regulations, and other requirements stipulated for the probation period.c) Suspension/Deferred Suspension: The suspension is deferred subject to a definite or indefinite period of observation and review. If a student is found responsible for a further violation of the university Student Disciplinary Regulations or an order of a judiciary body, suspension will take place immediately.Def i niteThe student is dropped from the university for a specific length of time. This suspension cannot be for less than one semester or more than two years.Indef i nite:The Student is dropped from the university indefinitely. Reinstatement may be contingent upon meeting the written requirements of the AUJ specified at the time the sanction was imposed. Normally, a student who is suspended indefinitely may not be reinstated for a minimum of two years.d) Expulsion: The student is permanently deprived of the opportunity to continue at the university in any status.5. A student accused of academic misconduct has the option to stay in the class or to drop the class if the drop is made within the approved time periods and according to the regulations established by the university. If the student chooses to drop the class, the student will be required to sign a statement of understanding that if the student is later found responsible for academic misconduct, then the student will receive an F for the course.6. Procedures for appeal of either the All University Judi ciary’s conduct decision or theinstructor’s grade are outlined in the Student Information Handbook.7. In instances in which the student admits responsibility or is judged to be responsible by OJA or the AUJ, a staff member of the Dean of Students Off ice will counsel the student in an effort to deter any further such incidents.8. Student records concerning academic dishonesty are maintained in the Dean of Students Office for a period of seven years, after which the file records are purged. These student records are confidential; nothing from them appears on a student’s academic transcript.9. In the event that an instructor is uncertain how to handle an incident of suspected academic dishonesty, the Dean of Students is available at any time to provide advice and assistance to the instructor in deciding a proper course of action to be taken.10. Students enrolled in the College of Veterinary Medicine are bound by an honor code. A chargeof academic dishonesty may be made by a student or instructor to the Interclass Honor Board chairperson according to the procedures outlined in the Honor Code, or the instructor may follow procedures outlined above. The Interclass Honor Board functions as the judiciary of the College of Veterinary Medicine for the allegations presented to it.Other violations related to academic misconduct may include subsection 4.1.11 Misuse of Computers and subsection 4.2.20 Unauthorized Sale of Others’Intellectual Works.These subsections are located in the Iowa State University Student Disciplinary Regulations under section 4 of the Conduct Code.</~catalog/2005-07/geninfo/dishonesty.html>Short reportAcademic dishonesty occurs when a student uses or attempts to use unauthorized information in the taking of an exam; or submits as his or her own work themes, reports, drawings, laboratory notes, or other products prepared by another person; or knowingly assists another student in such acts or plagiarism. Such behavior is abhorrent to the university, and students found responsible for academic dishonesty face expulsion, suspension, conduct probation, or reprimand. Instances of academic dishonesty ultimately affect all students and the entire university community by degrading the value of diplomas when some are obtained dishonestly, and by lowering the grades of students working honestly.Examples of specific acts of academic dishonesty include obtaining unauthorized information, tendering of information, misrepresentation, bribery, plagiarism, etc. Academic dishonesty is considered to be a violation of the behavior expected of a student in an academic setting as well as a student conduct violation.In Iowa State University, a student found responsible for academic dishonesty or academic misconduct is therefore subject to appropriate academic penalty or to be determined by the instructor of the course, as well as sanctions under the university Student Disciplinary Regulations. If an instructor believes that a student has behaved dishonestly in a course, ten steps are to be followed to handle the problem. The case of Iowa State UniversityResearch Paper WritingTask 1Background part:The introductionObjective:To give an overview of various forms of academic dishonesty, student responses to academic dishonesty when it occurs and the measures taken by the faculty and institutional administrator to prevent its occurrence in their institutions.Synthesis of different views on a particular field: For example, in the section “Forms of Academic Dishonesty,” in Para. B, there are opinions of both Jonson and Martin (2005) and Petress (2003), which are organized by transitional words, such as “Petress noted of other forms of academic dishonesty ...”Similarities or differences of outside sources:For example, in the section “Faculty and Academic Dishonesty”, when it comes to what the faculty should do to reduce academic dishonesty, there are various opinions from Para J to L. Perress (2003) holds that they should set role models for the students and implement the measures that will help prevent academic dishonesty. Whitley and Keith-Spiegel believe that they should be encouraged to form a statement concerning academic integrity in their syllabi and to discuss integrity concerns in their classrooms. Kibler notes four strategies to help the faculty to implement academic integrity. Cole and Kiss suggest that more efforts should be made to motivate the students by the teachers.Task 2a. The forms of cheating.Text 3 deals with students’ new and old techniques of cheating, together with researchers’ practices of academic dishonesty.Reading 1 focuses on academic dishonesty in online courses.Reading 1 gives more updated and reliable information.b. The reasons that students offer for their cheating.In Text 3 the reasons the students use to justify their cheating include: lack of time, poverty, uncaring instructors, laziness, peer pressure, poor role models, fear of failure and technology that has allowed cheating to be done easily. (Para. C)In Reading 1, the reasons are multifold because opinions vary. Some of the reasons are based on a student’s individual characteristics (Gerdeman 2001), some are relevant to peer inf luence or peers’acceptability of cheating (Stephens, 2007), while others have something to do with the existence of an honor code (McCabe, 2002). Meanwhile, there are other common reasons by Chiesl and Bunn, of which seeing other students cheat and the perception of the percentage of students who cheat are the most significant. (Para. I,J,K)Reading 1 gives more updated and reliable information.c. The definition of academic dishonesty.In Text 3, there is no specific definition of academic dishonesty.In Reading 1, the author believes that definitions of academic dishonesty across studies tend to be about the same. Using the scale of Don McCabe (2002), the author defines academic dishonesty from eight aspects. Other studies differentiate planned and panic cheating, e.g., Bunn, Caudill and Gropper (1992). In a comparative study of online versus on-ground academic dishonesty, Stuber- McEwen, Wisely, and Hoggat (2009) believe that there are seven forms. Stephens, Young, and Calabrese (2007) examined various forms of conventional and digital cheating. With regard toe-learning, Underwood (2003) and Rogers (2000) def ine the term respectively, while Howell et al (2009) reviews various forms of technological cheating. (Para.B, C, D, E, F, G)Reading 1Task 31) Serious and formal2) Angry and bitter3) Angry and ironical4) Angry and ironical5) Ironical6) Ironical7) Angry and ironical8) Angry9) Ironical10) Tranquil and formal11) Tranquil12) Tranquil and formal13) Formal and serious14) Formal and serious15) Expressing the speaker’s surprise and attitude against this16) Tranquil17) Expressing surprise, Ironical18) Appealing to the readers’ emotions by the use of questions, Ironical19) Appealing to the readers’ emotions by the use of questions, Angry and ironical20) “You” is used in the sentence to indicate people in general to appeal to their emotions, whichshortens the distance between the speaker and the readers21) Appealing to the readers’ emotions by the use of questions22) Appealing to the readers’ emotions by the use of facts and questions. Expressing the speaker’sdisagreementTask 41) Which one is a stand-alone literature review and which one is a literature review as a partof the paper?Text 3 and Reading 1: stand-alone literature reviewReading 2: literature review as a part of the paper2) What similarities and differences characterize the three papers in terms of writing style?Similarities: All of them follow almost the same pattern, i.e., introduction, body, and conclusion.Differences: Text 3 and reading 1 synthesize other people’s research and f indings to draw the conclusion, while Reading 2 uses the author’s own research and f indings. Therefore, in Reading 2 there is the part of “Methods”, which explains in detail the participants, materials, and design and procedure. The first-person narration is used to describe the process, which makes it less formal than the other two papers.3) What are the objectives of the three papers respectively?Text 3: To give an overview of various forms of academic dishonesty, student responses to academic dishonesty when it occurs and the measures taken by the faculty and institutional administrator to prevent its occurrence in their institutions.Reading 1: Examine perceptions of academic dishonesty in online and face-to-face courses, and discuss methods to reduce academic dishonesty in online courses.Reading 2: To investigate participants’ attitudes toward cheating and the effects of academic motivation, self-eff icacy, and academic integrity on cheating behaviors.4) How many aspects or sections do the two stand-alone literature review contain respectively?What are they?ThreeIntroduction, body, and conclusion5) Is the order of those aspects in each literature review logic al? And what’s the relationship?Yes.The literature review consists of three aspects: an introduction, a body, and a conclusion. The introduction part may tell the reason one is writing a review; the signif icance of the topic; the scope of the review; the organizational pattern of the review. The body will have a clear classif ication and synthesis of one’s reviewed readings in terms of chronological order or importance order. The conclusion should have a summary of the main agreements and disagreements in the literature and then any gaps or areas for further research. At last one’s overall perspective on the topic should be dealt with.6) How do the two authors illustrate their arguments in each section? Do they use their own research and f i ndings or synthesize other people’s research and f i ndings?By synthesizing other people’s research and f indings.No.Reading 2Task 51) indicate, is, identified, tend, will be2) predicted, was, have suggested, are, showed, appeared, were, wereTask 6A chimera is an individual composed of cells with different embryonic origins. The successful isolation of f ive human embryonic stem cell (HESC) lines in 1998 increased scientists’ ability to create human/non-human chimeras and prompted extensive bioethics discussion, resulting in what has been dubbed “the other stem cell debate” (Shreeve 2005). The debate about chimeras has focused on five main arguments. The Unnaturalness Argument explores the ethics of violatingnatural species boundaries. The Moral Confusion Argument alleges that the existence of entities that cannot be definitively classified as either human or non-human will cause moral confusion that will undermine valuable social and cultural practices. The Borderline-Personhood Argument focuses on great apes and concludes that their borderline-personhood confers a high enough degree of moral status to make most, if not all, chimeric research on them impermissible. The Human Dignity Argument claims that it is an affront to human dignity to give an individual “trapped” in the body of a non-human animal the capacities associated with human dignity. Finally, the Moral Status Framework maintains that research in which a non-human animal’s moral status is enhanced to that of a normal adult human is impermissible unless reasonable assurances are in place that its new moral status will be respected, which is unlikely given the motivations for chimeric research and the oversight likely to be provided.These arguments provide different rationales for restricting chimeric research and have different implications for the range of chimeric research that will be deemed unethical.</entries/chimeras/#Int>Task 71) Which sentences provide the background of the paper?Academic dishonesty is a problem that has been plaguing colleges and universities for generations. An investigation of any institution today will certainly reveal some forms of academic dishonesty.2) Which sentences form the literature review?Researchers of academic dishonesty vary in their reports of how many students cheat in college.3) What is the main limitation of the previous studies that the author mentioned?However, most research on academic dishonesty has relied primarily on self-reports of cheating behaviors.4) What’s the objective of the paper?The purpose of the study is to investigate participants’ attitudes toward cheating and the effects of academic motivation, self-efficacy, and academic integrity on cheating behaviors.5) What are the methods that the author will use?The present study includes an empirical portion in which participants are put in a situation in which cheating may be to their advantage.6) What is the author’s hypothesis?The hypothesis is that participants would be most likely to cheat when they are offered a monetary reward for success.Task 8Introduction 11) an introduction of the topic and its background2) a review about the previous studies3) the limitation of the previous studies4) a gap for the signif icance of the study5) the hypothesis of the author6) the objective of the paper7) the methodologyIntroduction 21) an introduction of the topic and its background2) a review about the previous studies and the limitation of the previous studies3) the limitation of the previous studiesTask 91) A2) B3) E4) C5) D6) FTask 10This paper details the strategies used for curbing academic dishonesty in online courses.Task 11Biologists have long known of patterns of inheritance, and eventually of inheritance mechanisms, that go beyond genetic inheritance (Jablonka & Lamb 2005; Sapp 1987). Two fundamental types of arguments led to this conclusion: arguments based on observations regarding patterns of inheritance, and arguments concerned with the localization of hereditary factors inside cells. Arguments of the first kind were based on hereditary relations and inheritance patterns that fail to conform to the rules ofMendelian inheritance (e.g., maternal inheritance). If Mendelian inheritance patterns are the result of the way the chromosomes in the eukaryotic cell nucleus behave, non-Mendelian heredity must depend on separate inheritance processes, mechanisms, or systems (Beale 1966; Sager 1966). Second, there were observations of hereditary phenomena that seemed to depend on factors residing in the cytoplasm of cells, rather than their nucleus, where the genetic material is localized. The interpretation of these observations was highly contested (Darlington 1944; Sapp 1987). Today, we know that some of these observations are related to the (maternal) inheritance of organelles residing in the cytoplasm, such as the mitochondria and chloroplasts, organelles which carry their own DNA. This however does not encompass all the mechanisms which underlie cytoplasmatic inheritance. Paradigmatic work on cytoplasmatic inheritance done by Sonneborn, Beale, Nanney, and their colleagues in the 1950s and 1960s, was concerned with patterns of inheritance in unicellular organisms, and in particular the protist genus Paramecium. It was suggested that the self-sustaining regulatory loops that maintain gene activity or inactivity in a cell would persist through cell division, provided the non-DNA components of the system (many of which reside in the cytoplasm in eukaryotic microogranisms) were shared among daughter cells. In this way, alternative regulatory phenotypic states would be inherited. Among the properties whose inheritance was studied were mating-type variations, serotype variations, and the structural or “surface inheritance” of ciliary structures. Remarkably, microsurgical changes to the ciliary structures on the surface of Paramecium cells are inherited by offspring. The stability of induced characters once the stimulus was removed (called “cellular memory”) and the number of generations characters were maintained varied widely.However, the results indicated that long-term stability and heritability need not be the result of changes to the DNA sequence (Nanney 1958).During the 1950s to 1970s a growing set of observations indicated that determined and differentiated states of cells are transmitted in cell lineages. These observations concerned studies of Drosophila imaginal discs by Ernst Hadorn; Briggs and King’s cloning experiments with amphibians; Mary Lyon’s work on X-chromosome inactivation; and work establishing the in vitro clonal stability of cultured cell lines. Eventually, the term epigenetic inheritance came to refer to hereditary variation that does not involve changes to the DNA sequence.The brief account of some of the early work on unicellular organisms given above illustrates some。

Unite 3 Doctor’s Dilemma: Treat or Let Die?Abigail Trafford1. Medical advances in wonder drugs, daring surgical procedures, radiation therapies, and intensive-care units have brought new life to thousands of people. Yet to many of them, modern medicine has become a double-edged sword.2. Doctor’s power to treat with an array of space-age techniques has outstripped the body’s capacity to heal. More medical problems can be treated, but for many patients, there is little hope of recovery. Even the fundamental distinction between life and death has been blurred.3. Many Americans are caught in medical limbo, as was the South Korean boxer Duk Koo Kim, who was kept alive by artificial means after he had been knocked unconscious in a fight and his brain ceased to function. With the permission of his family, doctors in Las Vegas disconnected the life-support machines and death quickly followed.4. In the wake of technology’s advances in medicine, a heated debate is taking place in hospitals and nursing homes across the country --- over whether survival or quality of life is the paramount goal of medicine.5. “It gets down to what medicine is all about, ” says Daniel Callahan, director of the Institute of Society, Ethics, and the Life Sciences in Hastings-on-Hudson, New York. “Is it really to save a life? Or is the larger goal the welfare of the patient?”6. Doctors, patients, relatives, and often the courts are being forced to make hard choices in medicine. Most often it is at the two extremes of life that these difficultyethical questions arise --- at the beginning for the very sick newborn and at the end for the dying patient.7. The dilemma posed by modern medical technology has created the growing new discipline or bioethics. Many of the country’s 127 medical s chools now offer courses in medical ethics, a field virtually ignored only a decade ago. Many hospitals have chaplains, philosophers, psychiatrists, and social workers on the staff to help patients make crucial decisions, and one in twenty institutions has a special ethics committee to resolve difficult cases.Death and Dying8. Of all the patients in intensive-care units who are at risk of dying, some 20 percent present difficult ethical choices --- whether to keep trying to save the life or to pull back and let the patient die. In many units, decisions regarding life-sustaining care are made about three times a week.9. Even the definition of death has been changed. Now that the heart-lung machine can take over the functions of breathing and pumping blood, death no longer always comes with the patient’s “last gasp” or when the heart stops beating. Thirty-one states and the District of Columbia have passed brain-death statutes that identify death as when the whole brain ceases to function.10. More than a do zen states recognize “living wills” in which the patients leave instructions to doctors not to prolong life by feeding them intravenously or by other methods if their illness becomes hopeless. A survey of California doctors showed that 20 to 30 percent were following instructions of such wills. Meanwhile, the hospicemovement, which its emphasis on providing comfort --- not cure --- to the dying patient, has gained momentum in many areas.11. Despite progress in society’s understanding of death and dying, t heory issues remain. Example: A woman, 87, afflicted by the nervous-system disorder of Parkinson’s disease, has a massive stroke and is found unconscious by her family. Their choices are to put her in a nursing home until she dies or to send her to a medical center for diagnosis and possible treatment. The family opts for a teaching hospital in New York city. Tests show the woman’s stroke resulted from a blood clot that is curable with surgery. After the operation, she says to her family: “Why did you bring me back to this agony?” Her health continues to worsen, and two years later she dies.12. On the other hand, doctors say prognosis is often uncertain and that patients, just because they are old and disabled, should not be denied life-saving therapy. Ethicists also fear that under the guise of medical decision not to treat certain patients, death may become too easy, pushing the country toward the acceptance of euthanasia.13. For some people, the agony of watching high-technology dying is too great. Earlier this year, Woodrow Wilson Collums, a retired dairyman from Poteet, Texas, was put on probation for the mercy killing of his older brother Jim, who lay hopeless in his bed at a nursing home, a victim of severe senility resul ting from Alzheimer’s disease. After the killing, the victim’s widow said: “I think God, Jim’s out of his misery. I hate to think it had to be done the way it was done, but I understand it. ”Crisis in Newborn Care14. At the other end of the life span, technology has so revolutionized newborn carethat it is no longer clear when human life is viable outside the womb. Newborn care has got huge progress, so it is absolutely clear that human being can survive independently outside the womb. Twenty-five years ago, infants weighting less than three and one-half pounds rarely survived. The current survival rate is 70 percent, and doctors are “salvaging” some babies that weigh only one and one-half pounds. Tremendous progress has been made in treating birth deformities such as spina bifida. Just ten years ago, only 5 percent of infants with transposition of the great arteries --- the congenital heart defect most commonly found in newborns --- survived. Today, 50 percent live.15. Yet, for many infants who owe their lives to new medical advances, survival has come at a price. A significant number emerge with permanent physical and mental handicaps.16. “The question of treatment and nontreatment of seriously ill newborns is not a single one,”says Thomas Murray of the Hastings Center. “But I feel strongly that retardation or the fact that someone is going to be less than perfect is not good grounds for allowing an infant to die.”17. For many parents, however, the experience of having a sick newborn becomes a lingering nightmare. Two years ago, an Atlanta mother gave birth to a baby suffering from Down’s Syndrome, a form of mental retardation; the child also had blocked intestines. The doctors rejected the parents’ plea not to operate, and today the child, severely retarded, still suffers intestinal problems.18. “Every time Melanie has a bowel movement, she cries,” explains her mother.“She’s not able to take care of herself, and we won’t live forever. I wanted to save her from sorrow, pain, and suffering. I don’t understand the emphasis on life at all costs, and I’m very angry at the doctors and the hospital. Who will take care of Melanie after we’re gone? Where will you doctors be then?”Changing Standards19. The choices posed by modern technology have profoundly changed the practice of medicine. Until now, most doctors have been activists, trained to use all the tools in their medical arsenals to treat disease. The current trend is toward nontreatment as doctors grapple with questions not just of who should get care but when to take therapy away.20. Always in the background is the threat of legal action. In August, two California doctors were charged with murdering a comatose patient by allegedly disconnecting the respirator and cutting off food and water. In 1981, a Massachusetts nurse was charged with murdering a cancer patient with massive doses of morphine but was subsequently acquitted.21. Between lawsuits, government regulations, and patients’ rights, many doctors feel they are under siege. Modern technology actually has limited their ability to make choices. More recently, these actions are resolved by committees.Public Policy22. In recent years, the debate on medical ethics has moved to the level of national policy. “It’s just beginning to hit us that we don’t have unlimited resources,” says Washington Hospital Center’s Dr. Lynch. “You can’t talk about ethics without talkingethics without talking about money.”23. Since 1972. Americans have enjoyed unlimited access to a taxpayer-supported, kidney dialysis program that offers life-prolonging therapy to all patients with kidney failure. To a number of police analysts, the program has grown out of control --- to a $1.4billion operation supporting 61,000 patients. The majority are over 50, and about a quarter have other illness, such as cancer or heart disease, conditions that could exclude them from dialysis in other countries.24. Some hospitals are pulling back from certain lifesaving treatment. Massachusetts General Hospital, for example, has decided not perform heart transplants on the ground that the high costs of providing such surgery help too few patients. Burn units --- through extremely effective --- also provide very expensive therapy for very few patients.25. As medical scientists push back the frontiers of therapy, the moral dilemma will continue to grow for doctors and patients alike, making the choice of to treat the basic question in modern medicine.1. 在特效药、风险性手术进程、放疗法以及特护病房方面的医学进展已为数千人带来新生。

概率与统计第⼋章：假设检验Chapter 8 Hypothesis TestingSection 8 - 2I. How to setup a hypothesis testing for µ or for p?Definition: The null hypothesis (Ho) is a statement asserting no change, no difference, or no effect. It contains an equal sign. Definition: The alternative hypothesis (Ha) is a statement that might be true instead of the null hypothesis. It usually contains the symbol > , < ,or ≠ .In hypothesis testing, the idea is to give the benefit of the doubt to the nullhypothesis. Ho will be rejected only if the sample data suggest beyond areasonable doubt that Ho is false.In hypothesis testing, Ha controls the tail(s) of the critical region(s).Example 1: For the claims in part (a) – (f), (i) find Ho and Ha, (ii) give thetype of critical region (right-tailed, left-tailed, or two tailed).(a) The mean temperature in a coastal town is less than 78?F.(b) The mean grade point average of graduating seniors at a universityis at least 2.3.(c) The mean income for L.A. Mission faculty is $4500 per month.(d) The proportion p of voters in a state who favor the death penaltyunder prescribed conditions is .53.(e) The proportion p of full-time college students younger than 26 yearsof age is at most .90.(f) The proportion of p of high school graduates in 1990 seeking full-timeemployment was more than .30.When testing a null hypothesis, a decision is made in rejecting Ho or failing to reject Ho. It is possible that the decision is wrong, even if we do everythingcorrectly. Two different types of errors, type I and type II errors, can be made.A type I error occurs if one rejects Ho when it is actually true.The level of significance is the maximum probability of committing a type I error. This probability is symbolized by α.A type II error occurs if one does not reject Ho when it is actually false.The symbol β is used to represent the probability of a type II error.Section 8 – 3 to Section 8 – 5I. Test StatisticA test statistic is a quantity that is used to make a decision in a test of hypotheses.Test Statistic for Testing a Claim about a MeanIf σ is known ,z =If σ is unknown but n ≥ 30,z =If σ is unknown and n < 30,t =Test Statistic for Testing a Claim about a Proportionz = where x p n =II. The Classical Approach to Hypothesis TestingStep 1: Identify Ho and HaHo will contain =Ha will contain > , < , or ≠Step 2: Select the test statistic and determine its value from the sample data.See the formulas given for II.Step 3: Use a given level of significance and Ha to determine the criticalregion(s).Step 4: Make your decision. If the test statistic falls in the critical region,reject Ho. If the test statistic does not fall in the critical region,we do not reject Ho. Interpret your decision in terms of the claim. Example 1: Full-time Ph.D. students receive an average salary of $12,837 according to the U.S. Department of Education. The dean ofgraduate studies at a large state university feels that Ph.D. studentsearn more than this. He surveys 44 randomly selected students andfinds their average salary is $14,445 with a standard deviation of$1,500. With = 0.05, is the dean correct?Example 2: The average U.S. wedding includes 125 guests. A randomsample of 35 weddings during the past year in a particularcounty had a mean of 110 guests and a standard deviationof 30. Is there sufficient evidence at the 0.01 level of signi-ficance that the average number of guests differs from thenational average?III. The P-value Approach to Hypothesis TestingStep 1: Identify Ho and HaHo will contain =Ha will contain > , < , or ≠Step 2: Select the test statistic and determine its value from the sample data. See the formulas given for I.Step 3: Omit the step of finding the critical region. Find the P-value associated with the value of the test statistic.Step 4: Make your decision. If the P-value ≤α , reject Ho.If the P-value > α , do not reject Ho.Interpret your decision in terms of the claim.Example 1: Find the P-value and decide whether to reject or not to reject the Ho. Assume α = 0.05.(a) Ho: µ = 80; Ha: µ > 80 Observed value: z = 1.75(b) Ho: µ = 15; Ha: µ < 15 Observed value: z = -.83(c) Ho: p= 0.60; Ha: p≠ 0.60 Observed value: z = -1.22(d) Ho: µ = 125; Ha: µ > 125 Observed value: t = 1.58n = 25(e) Ho: µ = 60; Ha: µ≠ 60 Observed value: t = -1.78n = 8Example 2: A college professor claims that the average cost of a paperback textbook is greater than $27.50. A sample of 50 books has an average costof $29.30. The standard deviation of the sample is $5.00. Find the P-valuefor the test. On the basis of the P-value, should the null hypothesis be rejected at α = 0.05? Is there sufficient evidence to conclude that the professor’s claim is correct?Example 3: The average amount of rainfall during the summer months for the northeast part of the United States is 11.52 inches.A researcher selects a random sample of 10 cities in the northeast andfinds that the average amount of rainfall for 1995 was 7.42 inches. The standard deviation of the sample is 1.3 inches. At α = 0.05, can it be concluded that for 1995 the mean rainfall was below 11.52 inches?Assume the population is approximately normal.Example 4: A retailer has received a large shipment of VCRs. He decided to accept the shipment provided there is no evidence to suggest that the shipment contains more than 5% non-acceptable items. The retailer found14 non-acceptable items in a random selection of 160 items. At a 5% levelof significance, what is the retailer’s decision?Example 5: In a recent presidential election, 611 voters were surveyed, and308 of them said that they voted for the candidate who won.Use a 0.04 significance level to test the claim that among all voters, 43%say that they voted for the winning candidate.Example 6: Data were obtained from one section of a mathematics course taught by a good instructor. For past classes, the mean final exam score for thiscourse is 70. Prior to the final exam, the instructor was interested inwhether the mean final exam score for his section containing 14 studentswould be statistically significantly higher than 70.A stem-and-leaf plot is given.5 0 06 1 1 2 37 0 3 4 58 0 29 2 9(a) Is the t procedure appropriate in this case? If so, proceed to part (b).(b) Find the mean and standard deviation for this class.(c) Using a 5% level of significance, can the teacher conclude that the meanperformance of the class is larger than 70?。

hypothesesHypothesesIntroductionIn the world of scientific research, hypotheses play a critical role in the formulation of experiments and studies. A hypothesis is a statement or assumption that is made based on limited evidence or observations and serves as a starting point for further investigation. This document aims to explore the concept of hypotheses, their importance, and how they are formulated and tested in various scientific disciplines.What is a Hypothesis?A hypothesis is a proposed explanation or prediction for a phenomenon or a question that can be tested. It is an essential element of the scientific method and is used to guide research and experiments. Hypotheses are usually based on existing knowledge, previous observations, or theories, and serve as an attempt to explain or predict a particular phenomena.Formulating a HypothesisThe process of formulating a hypothesis requires careful consideration of the existing knowledge and evidence. To develop a hypothesis, researchers typically follow a few key steps:1. Identify the research question: The first step in formulatinga hypothesis is to clearly identify the research question or problem that needs to be addressed. This question should be specific and focused to provide a clear direction for the research.2. Review existing knowledge: Once the research question is identified, it is important to review the existing knowledge and literature related to the topic. This helps in understanding previous findings and theories that can inform the formulation of a hypothesis.3. Generate possible explanations: Based on the existing knowledge, researchers generate possible explanations or predictions for the research question. These explanations are known as hypotheses and should be testable and falsifiable.4. Refine the hypothesis: After generating the initial hypotheses, researchers refine and narrow down the options to develop a more focused and specific hypothesis. This is done by considering factors such as feasibility, relevance, and available resources.Testing a HypothesisOnce a hypothesis is formulated, it needs to be tested through experimentation or observation. The process of testing a hypothesis involves the following steps:1. Design the experiment: The researcher designs an experiment or study that will allow them to collect data and test the hypothesis. The design of the experiment should be carefully planned to ensure that it provides valid and reliable results.2. Collect and analyze data: During the experiment, data is collected and analyzed to determine whether the results support or refute the hypothesis. Statistical analysis is often used to evaluate the significance of the findings and to draw meaningful conclusions.3. Draw conclusions: Based on the analysis of the data, the researcher draws conclusions about the hypothesis. If the results support the hypothesis, it is considered to be validated. On the other hand, if the results contradict the hypothesis, it may be necessary to revise the hypothesis or develop new ones for further investigation.Importance of Hypotheses in Scientific ResearchHypotheses are a fundamental aspect of scientific research for several reasons:1. Guiding research: Hypotheses provide a clear direction for research, allowing researchers to focus their efforts on specific questions or problems. They help in organizing the research process and ensuring that it is purposeful and systematic.2. Promoting objectivity: Hypotheses help in maintaining objectivity in scientific research by providing a framework for testing and evaluating ideas. They prevent bias and ensure that the research is based on evidence and logic rather than personal opinions or beliefs.3. Advancing knowledge: By formulating hypotheses and testing them through rigorous experimentation, researchers contribute to the advancement of knowledge in their respective fields. Hypotheses that are supported by evidence can lead to new discoveries and insights.4. Identifying limitations: Hypotheses allow researchers to identify and address the limitations of existing knowledge and theories. They highlight the gaps in understanding and provide opportunities for further investigation and refinement of theories.ConclusionHypotheses are a critical component of scientific research. They provide a starting point for investigation, guide research efforts, and contribute to the advancement of knowledge. By formulating and testing hypotheses, researchers can better understand the world around us and make meaningful contributions to their respective fields.。

1.What is the main idea of the passage?A.The history of technology.B.The impact of social media.C.The benefits of exercise.（答案）D.The challenges of modern education.2.Which word best describes the author's tone in the text?A.SarcasticB.Optimistic（答案）C.PessimisticD.Neutral3.What does the phrase "in the long run" mean in the context?A.ImmediatelyB.Eventually（答案）C.OccasionallyD.Rarely4.According to the passage, what is the most effective way to learn a new language?A.Watching foreign movies.B.Listening to music in that language.C.Practicing with a language tutor.（答案）D.Reading books translated into that language.5.Why did the scientist decide to conduct the experiment?A.To prove a previous theory wrong.B.To discover a new element.C.To test a new hypothesis.（答案）D.To replicate a famous study.6.What is the purpose of the author writing this article?A.To entertain readers with a story.B.To persuade readers to adopt a new habit.（答案）C.To inform readers about a recent event.D.To analyze a complex issue.7.Which of the following is NOT mentioned in the passage as a cause of climate change?A.DeforestationB.OverpopulationC.Increased use of renewable energy（答案）D.Industrial emissions8.What can be inferred from the last sentence of the passage?A.The problem will never be solved.B.More research is needed.（答案）C.The solution is simple and straightforward.D.The author is uncertain about the future.。

Science experiments are an integral part of the educational curriculum,fostering critical thinking,observation,and analytical skills.In this essay,I will discuss the importance of conducting science experiments,the steps involved in a typical experiment, and the benefits of integrating them into the learning process.Importance of Conducting Science ExperimentsScience experiments are crucial for several reasons.Firstly,they provide a handson approach to learning,allowing students to engage with scientific concepts in a practical manner.This active involvement helps to solidify understanding and retention of the material.Secondly,experiments encourage curiosity and exploration,pushing students to question the world around them and seek answers through empirical evidence.Steps Involved in a Typical Science Experiment1.Hypothesis Formulation:The process begins with the development of a hypothesis,a testable statement that predicts the outcome of the experiment based on existing knowledge or theories.2.Experiment Design:Students must design an experiment that can test their hypothesis effectively.This involves selecting the appropriate materials,methods,and controls.3.Data Collection:Once the experiment is set up,data is collected through observation and measurement.Its essential to record data accurately and systematically.4.Analysis:After data collection,the next step is to analyze the results.This involves interpreting the data to determine whether the hypothesis was supported or refuted.5.Conclusion:Based on the analysis,a conclusion is drawn.This should clearly state whether the original hypothesis was correct and provide insights into the findings.6.Reflection and Further Inquiry:Finally,students should reflect on the experiment, considering any limitations or areas for improvement,and propose further questions for investigation.Benefits of Integrating Science Experiments into Learning1.Enhanced Understanding:Experiments provide a deeper understanding of scientific principles by allowing students to see the concepts in action.2.Development of ProblemSolving Skills:The process of designing and conducting an experiment requires students to solve problems,think critically,and adapt to unexpected results.3.Encouragement of Creativity:Experiments often require innovative thinking,as students must come up with novel ways to test their hypotheses.4.Fostering Collaboration:Group experiments teach teamwork and communication skills, as students must work together to achieve a common goal.5.Preparation for Future Studies and Careers:Science experiments prepare students for higher education and careers in science,technology,engineering,and mathematics STEM fields by providing a solid foundation in scientific inquiry.In conclusion,science experiments are a vital component of education that not only enhance learning but also equip students with essential skills for their future.By engaging in these activities,students gain a deeper appreciation for the scientific method and its applications in understanding the world around them.。

critical period hypothesis的定义The critical period hypothesis is a concept in the field of linguistics that suggests that there is a specific period in childhood during which language acquisition occurs more easily and successfully. According to this hypothesis, if a person does not acquire their first language within this critical period,they may struggle to achieve fluency and proficiency in that language later in life. 。

The critical period hypothesis was first proposed bylinguist Eric Lenneberg in 1967. He argued that there is a neurological basis for language acquisition and that after a certain age, the brain loses its plasticity, making it more difficult to acquire a new language. Lenneberg suggested thatthe critical period for language development ends around puberty, although the e某act age range can vary. 。