Unit8

1. Unit8 Preview Ⅰ. Objectives Ⅱ. Suggested Teaching Plan Ⅲ. Background Information Ⅳ. Class Presentation

2. prev. Preview This is the last unit of Book Two. In the Listening and Speaking section, you will learn how to ask for and give reasons. In the Reading and Writing section, you will read three passages about science and technology. Text A was written at the turn of the 21st century and the writer predicted the top five scientific developments of the coming century. Text B concerns issues of safety that must be guaranteed when the frontier of science and technology is being pushed back. Text C deals with the issue of recycling.

3. master the basic language and skills necessary to ask for and give reasons; 1. understand the main ideas of Text A, Text B and Text C, and master the useful sentence structures and words and expressions found in the exercises relevant to the first two texts; 2. 3. know how to use the inverted order; know how to write an email; 4. understand paragraph development (5). 5. Obj. Ⅰ. Objectives After studying this unit, the students are expected to be able to

4. s.t.p.1 Ⅱ. SuggestedTeaching Plan Suggested Time and Teaching Plan for Unit 8 Plan Contents Time The teacher begins with the Preview to make sure that the students have a general idea of what this unit is all about. After that, the teacher activates listening and Speaking exercises as follows: 2 periods Preview & 1) The Language for Asking For and Giving Reasons Listening and Speaking Give a brief lead-in talk on the nature and uses of asking for and giving reasons; A. B. Present the necessary language by doing Exercise 1;

5. s.t.p.1.2 Time Contents Plan C. Ask one student to read aloud the talk so students can check their completed answers; Organize an activity for Exercise 2 that will reinforce the useful language students picked up in Exercise 1. D. 2) The Practice of Asking For and Giving Reasons A. Go through the new words in the first conversation in Exercise 3; Have the students listen to the conversation twice and fill in the blanks with the missing words; B. C. Ask them to answer the questions about the conversation;

6. s.t.p.2 Time Contents Plan Tell them to look for the language used to asking for and giving reasons; D. E. Ask the students to role-play the conversation; F. Have them listen to the second conversation twice and complete the short passage accordingly; Suggest they discuss each of their completed answers in order to gain a better understanding of the conversation; G. H. Now, have them listen to the conversation again and complete the form as the speaker recounts it; I. Afterwards, have them check their responses by acting out the conversation;

7. s.t.p.3 Time Contents Plan J. Organize a unique classroom activity for Exercise 4 that will reinforce the useful language students picked up earlier in the unit. 3) Listening Practice Before ending, the teacher tells the students to do Exercises 5-10 as their assignment to review the functional and notional language picked up in the Listening and Speaking section. The teacher also tells them that they should be prepared to answer the questions in Exercise 9 and give an oral presentation in class when they next meet.

8. s.t.p.4 Time Contents Plan 3 periods The teacher begins with a review of the functional and notional language the students picked up in the previous classes. The teacher asks several students to answer the questions in Exercise 9 of the Listening and Speaking section, and invites a few to share with their classmates their opinions on the topic “It is more important to raise a question than to answer a question.” Then, the teacher turns to the Reading and Writing section. (These activities should be completed in 15 minutes.) Review of the listening and speaking skills the students have learned

9. s.t.p.5 Time Contents Plan Text A & text-related exercises 1) Starter After a brief explanation of the instructions, the teacher gives the students a few minutes to think about the questions in the starter; A. asks some students to answer the questions. B. 2) Text A The teacher lets the students answer the text-related questions, helps them identify the main idea of each paragraph, and analyzes some difficult sentences and some language A.

10. s.t.p.8 Time Contents Plan points while discussing the whole text with the students (one and a half periods); guides the students through the exercises, focusing on certain items or leaving some exercises as the students homework according to the students different levels of English (one period). B. Grammar Review 1) Grammar Review 1 period The teacher talks about the use of the inverted order, and at the same time asks the students to do the grammar exercises in class.

11. s.t.p.9 Time Contents Plan 2) Practical Writing Practical Writing The teacher explains to the students how to write an email by doing Exercise 11 of Practical Writing, and then requires the students to do Exercise 12 after class.

12. s.t.p.10 Time Contents Plan 1) Text B 2 periods Text B, Text C & Text-related exercises While discussing the text with the students, the teacher calls on them to pay attention to the structure of the paragraphs of the text, introducing briefly the concept of the topic sentence. Exercises 14 and 15 can be done either in or after class. 2) Text C This text should be read by the students themselves as their homework or done as fast-reading in class.

13. s.t.p.11 Time Contents Plan Basic Reading Skills 3) Basic Reading Skills The teacher explains to the students paragraph development (5), and asks them to do the exercises in Basic Reading Skills.

14. BI Ⅲ. BackgroundInformation James Trefil Original Text of “The Top 5 Scientific Breakthroughs of the 21st Century” Modern Science (20th century) Three Mile Island The Chernobyl Accident Radiation sickness Soviet Union and Russia

15. BI-JT James Trefil As an award-winning author and physicist, James Trefil has written more than 25 books on a range of science topics. He’s a contributor to National Public Radio and Smithsonian Magazine, and a physics professor at Virginia’s George Mason University, U.S.A.

16. BI-OT1 Original Text of “The Top 5 Scientific Breakthroughs of the 21st Century” (其中提及了作者进行预测的根据) James Trefil The 20th century produced scientific and technological change at a dizzying pace-greater than in any other century in history. But the 21st century, the dawn of the new millennium, may well see even more dramatic change driven by advances in science and technology. On these pages are my predictions for the top scientific developments we’ll see in the next 100 years, in the order I think they’ll happen.

17. BI-OT2 1. We’ll know where we came from Why does the universe exist? To put it another way, why is there something instead of nothing? Since the 1920s, scientists have known the universe is expanding, which means it must have started at a definite time in the past. They even have developed theories that give a detailed picture of the evolution of the universe from the time it was a fraction of a second old to the present. Over the next couple of decades, these theories will be refined by data from extraordinarily powerful new telescopes and advances in our understanding of how matter behaves at the unfathomably high temperatures and pressures of the early universe. Margaret Geller of the Harvard-Smithsonian Center for Astrophysics, a pioneer in exploring the structure of the universe, believes that “by 2100, we will have a complete map of all the galaxies in the visible universe.” Considering that the first primitive maps of North America (produced by explorers who followed Columbus) appeared only 500 years ago, a mere century to map every galaxy within 15 billion light-years of Earth seems a breathtaking accomplishment.

18. BI-OT3 2. We’ll crack the genetic code and conquer cancer In 19th-century operas, when the heroine coughs in the first act, the audience knows she will die of tuberculosis in Act 3. But thanks to 20thcentury antibiotics, the once-dreaded, once-incurable disease now can mean nothing more serious than taking some pills. As scientists learn more about the genetic code and the way cells work at the molecular level, many serious diseases — cancer, for one — will become less threatening. Using manufactured “therapeutic” viruses, doctors will be able to replace cancer-causing damaged DNA with healthy genes, probably administered by a pill or injection. French Anderson of the University of Southern California Medical School, who did the first gene-therapy treatment on a human, predicts that “in 15 or 20 years, the majority of diseases will be treatable in this way.” By the end of the next century, people will look at our fear of cancer the way we now look at the operatic fear of TB: as a quaint relic of an immature technology.

19. BI-OT4 3. We’ll live longer (120 years?) If the normal aging process is basically a furious, invisible contest in our cells — a contest between damage to our DNA and our cells’ ability to repair that damage — then 21st-century strides in genetic medicine may let us control and even reverse the process. Experts in this field distinguish between increasing longevity (extending the average life span — now 76.5 years in the United States — as we have been doing for centuries) and increasing the maximum possible life span (which seems to be about 120 years). No doubt we can achieve the first, but experts are reluctant to speculate about the second. Says Rita Effros of the UCLA School of Medicine, a leading researcher on aging and the immune system: “I think 120 years of good health is enough for anyone.” So before we push scientists to do more, consider: Do we really want to live in a world where no one grows old and (presumably) few children are born because the planet can hold only so many people? Where would new ideas come from? What would we do with all that extra time? And would you really want to be a deputy assistant manager for 500 years?

20. BI-OT6 4. We’ll “manage” Earth In the next millennium, we’ll stop talking about the weather and do something about it. David Tilman of the University of Minnesota, a pioneer in developing and testing ecological theories, says, “The world’s ecosystems are incredibly complex, and the job of understanding them is made harder by the fact that they are being changed by the influence of human beings.” As we build bigger and faster computers, however, the mystery and unpredictability will start to fade. We’ll gradually learn how to predict the effects of human activity on the Earth, its climate and its ecosystems. And with that knowledge will come an increasing willingness to use it to manage the workings of our planet. Earth will be managed, like a farm or a game preserve. The Dutch have been doing this sort of thing on a smaller scale for centuries in managing their system of dikes. I see no reason humanity organized in a global village can’t do the same.

21. BI-OT5 5. We’ll have a brain “road map” This is the real “final frontier” of the 21st century: The brain is the most complex system we know. It contains about 100 billion neurons (roughly the number of stars in the Milky Way), each connected to as many as 1,000 others. Early in the next century, we will use advanced forms of magnetic resonance imaging to produce detailed maps of the neurons in operation. We’ll be able to say with certainty which ones are working when you read a word, when you say a word, when you think about a word, and so on. Steven Pinker of the Massachusetts Institute of Technology, noted psychologist and author of the book How the Mind Works, predicts that in the next century “we’ll learn a lot about things we don’t understand today: human emotions, social relationships, reasoning and decision-making.” We’ll see new treatments for specific mental conditions (as today’s Prozac treats depression). We’ll develop medicines that enhance mental functions — like the steroids athletes use to promote muscle growth, but without the harmful side effects.

22. BI-OT7 So with this fifth prediction we come full circle, and realize that the most difficult thing to understand in the universe may be the 3-pound organ we carry around in our skulls — the organ that allows us to understand the universe in the first place.

23. BI-MS1 Modern Science (20th century) In the 20th century, scientists achieved spectacular advances in the fields of genetics, medicine, social sciences, technology, and physics. 1. Genetics At the beginning of the 20th century, the life sciences entered a period of rapid progress. Mendel’s work in genetics was rediscovered in 1900, and by 1910 biologists had become convinced that genes are located in chromosomes, the threadlike structures that contain proteins and deoxyribonucleic acid (DNA). During the 1940s American biochemists discovered that DNA taken from one kind of bacterium could influence the characteristics of another. From these experiments, it became clear that DNA is the chemical that makes up genes and thus the key to heredity.

24. BI-MS2 After American biochemist James Watson and British biophysicist Francis Crick established the structure of DNA in 1953, geneticists became able to understand heredity in chemical terms. Since then, progress in this field has been astounding. Scientists have identified the complete genome, or genetic catalog, of the human body (see Human Genome Project). In many cases, scientists now know how individual genes become activated and what effects they have in the human body. Genes can now be transferred from one species to another, side-stepping the normal processes of heredity and creating hybrid organisms that are unknown in the natural world (see Transgenic Organism).

25. BI-MS3 2. Medicine At the turn of the 20th century, Dutch physician Christiaan Eijkman showed that disease can be caused not only by microorganisms but by a dietary deficiency of certain substances now called vitamins. In 1909 German bacteriologist Paul Ehrlich introduced the world’s first bactericide, a chemical designed to kill specific kinds of bacteria without killing the patient’s cells as well. Following the discovery of penicillin in 1928 by British bacteriologist Sir Alexander Fleming, antibiotics joined medicine’s chemical armory, making the fight against bacterial infection almost a routine matter. Antibiotics cannot act against viruses, but vaccines have been used to great effect to prevent some of the deadliest viral diseases. Smallpox, once a worldwide killer, was completely eradicated by the late 1970s, and in the United States the number of polio cases dropped from 38,000 in the 1950s to less than 10 a year by the 21st century.

26. BI-MS4 By the middle of the 20th century scientists believed they were well on the way to treating, preventing, or eradicating many of the most deadly infectious diseases that had plagued humankind for centuries. But by the 1980s the medical community’s confidence in its ability to control infectious diseases had been shaken by the emergence of new types of disease-causing microorganisms. New cases of tuberculosis developed, caused by bacteria strains that were resistant to antibiotics. New, deadly infections for which there was no known cure also appeared, including the viruses that cause hemorrhagic fever and the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome. In other fields of medicine, the diagnosis of disease has been revolutionized by the use of new imaging techniques, including magnetic resonance imaging and computed tomography. Scientists were also on the verge of success in curing some diseases using gene therapy, in which the insertion of normal or genetically altered genes into a patient’s cells replaces nonfunctional or missing genes.

27. BI-MS5 Improved drugs and new tools have made surgical operations that were once considered impossible now routine. For instance, drugs that suppress the immune system enable the transplant of organs or tissues with a reduced risk of rejection (see Medical Transplantation). Endoscopy permits the diagnosis and surgical treatment of a wide variety of ailments using minimally invasive surgery. Advances in high-speed fiber-optic connections permit surgery on a patient using robotic instruments controlled by surgeons at another location. Known as telemedicine, this form of medicine makes it possible for skilled physicians to treat patients in remote locations or places that lack medical help.

28. BI-MS6 3. Social Sciences In the 20th century the social sciences emerged from relative obscurity to become prominent fields of research. Austrian physician Sigmund Freud founded the practice of psychoanalysis, creating a revolution in psychology that led him to be called the “Copernicus of the mind.” In 1948 the American biologist Alfred Kinsey published Sexual Behavior in the Human Male, which proved to be one of the best-selling scientific works of all time. Although criticized for his methodology and conclusions, Kinsey succeeded in making human sexuality an acceptable subject for scientific research. The 20th century also brought dramatic discoveries in the field of anthropology, with new fossil finds helping to piece together the story of human evolution. A completely new and surprising source of anthropological information became available from studies of the DNA in mitochondria, cell structures that provide energy to fuel the cell’s activities. Mitochondrial DNA has been used to track certain genetic diseases and to trace the ancestry of a variety of organisms, including humans.

29. BI-MS7 4. Technology In the field of communications, Italian electrical engineer Guglielmo Marconi sent his first radio signal across the Atlantic Ocean in 1901. American inventor Lee De Forest invented the triode, or vacuum tube, in 1906. The triode eventually became a key component in nearly all early radio, radar, television, and computer systems. In 1920 Scottish engineer John Logie Baird developed the Baird Televisor, a primitive television that provided the first transmission of a recognizable moving image. In the 1920s and 1930s American electronic engineer Vladimir Kosma Zworykin significantly improved the television’s picture and reception. In 1935 British physicist Sir Robert Watson-Watt used reflected radio waves to locate aircraft in flight. Radar signals have since been reflected from the Moon, planets, and stars to learn their distance from Earth and to track their movements (see Radar Astronomy).

30. BI-MS8 In 1947 American physicists John Bardeen, Walter Brattain, and William Shockley invented the transistor, an electronic device used to control or amplify an electrical current. Transistors are much smaller, far less expensive, require less power to operate, and are considerably more reliable than triodes. Since their first commercial use in hearing aids in 1952, transistors have replaced triodes in virtually all applications. During the 1950s and early 1960s minicomputers were developed using transistors rather than triodes. Earlier computers, such as the electronic numerical integrator and computer (ENIAC), first introduced in 1946 by American physicist John W. Mauchly and American electrical engineer John Presper Eckert, Jr., used as many as 18,000 triodes and filled a large room. But the transistor initiated a trend toward microminiaturization, in which individual electronic circuits can be reduced to microscopic size. This drastically reduced the computer’s size, cost, and power requirements and eventually enabled the development of electronic circuits with processing speeds measured in billionths of a second.

31. BI-MS9 Further miniaturization led in 1971 to the first microprocessor-a computer on a chip. When combined with other specialized chips, the microprocessor becomes the central arithmetic and logic unit of a computer smaller in size than a portable typewriter. With their small size and a price less than that of a used car, today’s personal computers are many times more powerful than the physically huge, multimillion-dollar computers of the 1950s. Once used only by large businesses, computers are now used by professionals, small retailers, and students to perform a wide variety of everyday tasks, such as keeping data on clients, tracking budgets, and writing school reports. People also use computers to interface with worldwide communications networks, such as the Internet and the World Wide Web, to send and receive e-mail, to shop, or to find information on just about any subject.

32. BI-MS10 During the early 1950s public interest in space exploration developed. The focal event that opened the space age was the International Geophysical Year from July 1957 to December 1958, during which hundreds of scientists around the world coordinated their efforts to measure the Earth’s near-space environment. As part of this study, both the United States and the Soviet Union announced that they would launch artificial satellites into orbit for nonmilitary space activities. When the Soviet Union launched the first Sputnik satellite in 1957, the feat spurred the United States to intensify its own space exploration efforts. In 1958 the National Aeronautics and Space Administration (NASA) was founded for the purpose of developing human spaceflight. Throughout the 1960s NASA experienced its greatest growth. Among its achievements, NASA designed, manufactured, tested, and eventually used the Saturn rocket and the Apollo spacecraft for the first manned landing on the Moon in 1969 (see Apollo Program). In the 1960s and 1970s, NASA also

33. BI-MS11 developed the first robotic space probes to explore the planets Mercury, Venus, and Mars (see Mariner). The success of the Mariner probes paved the way for the unmanned exploration of the outer planets in Earth’s solar system. In the 1970s through 1990s, NASA focused its space exploration efforts on a reusable space shuttle, which was first deployed in 1981. In 1998 the space shuttle, along with its Russian counterpart known as Soyuz, became the workhorses that enabled the construction of the International Space Station. 5. Physics In 1900 the German physicist Max Planck proposed the then sensational idea that energy is not infinitely divisible but is always given off in set amounts, or quanta. Five years later, German-born American physicist Albert Einstein successfully used quanta to explain the photoelectric effect, which is the release of electrons when metals are bombarded by light. This, together with Einstein’s special and general theories of relativity, challenged some of the most fundamental assumptions of the Newtonian era.

34. BI-MS12 Unlike the laws of classical physics, quantum theory deals with events that occur on the smallest of scales. Quantum theory explains how subatomic particles form atoms, and how atoms interact when they combine to form chemical compounds. Quantum theory deals with a world where the attributes of any single particle can never be completely known-an idea known as the uncertainty principle, put forward by the German physicist Werner Heisenberg in 1927. But while there is uncertainty on the subatomic level, quantum physics successfully predicts the overall outcome of subatomic events, a fact that firmly relates it to the macroscopic world-that is, the one in which we live. In 1934 Italian-born American physicist Enrico Fermi began a series of experiments in which he used neutrons (subatomic particles without an electric charge) to bombard atoms of various elements, including uranium. The neutrons combined with the nuclei of the uranium atoms to produce what he thought were elements heavier than uranium, known as transuranium elements. In 1939 other

35. BI-MS13 scientists demonstrated that in these experiments Fermi had not formed heavier elements, but instead had achieved the splitting, or fission, of the uranium atom’s nucleus. These early experiments led to the development of fission as both an energy source (see Nuclear Energy) and a weapon (see Atomic Bomb). These fission studies, coupled with the development of particle accelerators in the 1950s, initiated a long and remarkable journey into the nature of subatomic particles that continues today. Far from being indivisible, scientists now know that atoms are made up of 12 fundamental particles known as quarks and leptons, which combine in different ways to make all the kinds of matter currently known. Advances in particle physics have been closely linked to progress in cosmology. From the 1920s onward, when the American astronomer Edwin Hubble showed that the universe is expanding, cosmologists have sought to rewind the clock and establish how the universe began. Today, most scientists

36. BI-MS14 believe that the universe started with a cosmic explosion some time between 10 and 20 billion years ago (see Big Bang Theory). However, the exact sequence of events surrounding its birth, and its ultimate fate, are still matters of ongoing debate. (By David Burnie. From the Microsoft Encarta Reference Library 2004)

37. BI-TM Three Mile Island Three Mile Island is an island in the Susquehanna River in Dauphin County, Pennsylvania, near Harrisburg, of area 3.29 km2 (814 acres). The name is most commonly associated with an accident at the Three Mile Island Nuclear Generating Station on March 28, 1979, when reactor TMI-2 suffered a partial core meltdown. No identifiable injuries due to radiation occurred (although a government report by L. Battist et. al. stated that “the projected number of excess fatal cancers due to the accident … is approximately one.”) It was, however, a serious economic and public relations disaster. It also furthered a serious decline in the public popularity of nuclear power. (From the Wikipedia)

38. BI-TCA1 The Chernobyl Accident There have been different reports about the consequences of the accident. Two different versions have been presented below. Version One The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel and without proper regard for safety. The resulting steam explosion and fire released at least five percent of the radioactive reactor core into the atmosphere and downwind. Some 31 people were killed, and there have since been around ten deaths from thyroid cancer due to the accident. An authoritative UN report in 2000 concluded that there is no scientific evidence of any significant radiation-related health effects to most people exposed. (From the Nuclear Issues Briefing Paper 22, The UIC)

39. BI-TCA2 Version Two In 1986, an explosion and fire at the nuclear power plant in Chernobyl, near Kiev, released large amounts of radioactive material into the atmosphere. Nuclear fallout from the accident caused many health and environmental problems. Soviet officials claimed only 31 people died from the accident and about 200 were seriously injured. But in the early 1990’s, Ukrainian officials estimated that 6,000 to 8,000 people died as a result of the explosion and its aftermath. The disaster has caused high rates of cancer and other illnesses in Ukraine, Belarus, and Russia. (From the 1998 World Book Multimedia Encyclopedia)

40. BI-RS1 Radiation sickness Radiation sickness is the term for a variety of symptoms that follow a person’s exposure to damaging amounts of certain types of radiation. The radiation may come from nuclear explosions and the resulting fallout, from medical and industrial uses of radioisotopes, or from particle accelerators or X-rays machines. Ionization from the radiation causes a series of reactions in tissue that results in damage to the body’s cells. Exposures to high levels of radiation may cause lasting injury or even death. Some types of cells are more easily injured by radiation than others. The most sensitive cells are those of the blood-forming bone marrow and lymphoid tissues and those of a human embryo. Adult muscle and brain cells are the least sensitive to radiation.

41. BI-RS2 Scientists use a unit called the rem as a measure of radiation exposure. Over a lifetime, a person typically receives 7 to 14 rems from natural sources of radiation, such as cosmic rays. A single exposure of 5 to 75 rems produces few observable symptoms. Vomiting, fatigue, and loss of appetite accompany exposures of 75 to 200 rems, and recovery takes a few weeks. Severe changes in blood cells and hemorrhage occur with exposures of more than 300 rems. Above 600 rems, additional symptoms include loss of hair and loss of the body’s ability to fight infection, usually resulting in death. Doctors can treat only the symptoms of radiation sickness. Blood transfusions and the use of antibiotics to fight infection are common treatments. (From the 1998 World Book Multimedia Encyclopedia)

42. BI-SU Soviet Union and Russia The Union of Soviet Socialist Republics (U.S.S.R.) existed from 1922 to 1991. In 1991, the Soviet Union broke up into a number of independent states. Russia is the world’s largest country in area. It is almost twice as big as Canada, the second largest country. From 1922 until 1991, Russia was the biggest republic in the Soviet Union. After the Soviet Union broke apart in 1991, Russia began to set up a new political, legal, and economic system.

43. Class list Ⅳ. Class Presentation Listening & Speaking Reading & Writing Time for Fun

44. LS Listening & Speaking The Language for Asking For and Giving Reasons Asking For and Giving Reasons Listening Practice

45. Lp-main Listening Practice Listen to the following people talking and infer the appropriate responses. Listen to the following five short dialogues and choose the appropriate answers. Listen to the following short story twice. Listen carefully and decide whether the statements are true (T) or false (F) according to the story you have heard. Listen to the following talk and fill in the blanks with the missing words. The talk is given twice. Listen to the talk again and then answer the following questions orally. Have a discussion on the topic given below.

46. TL1 The Language for Asking For and Giving Reasons You are going to listen to an instructor explaining the language necessary for asking for and giving reasons. Listen carefully and fill in the blanks with the missing words. Instructor: We are interested in what is going on . We tend to around us ________ ask “why” because whatever happens in the physical world or among us, there is a reason . Since we are unknown, we push through scientific frontiers (前沿) to . To live is . Raising questions and asking for answers can sharpen (使敏锐) our minds. _______ behind it ______________ curious about the to know explore it ______ ________ Pick up the following sentences to ask for reasons: _____________________ we have different seasons — Do you know why ? — Why do you think ? — What’s the reason ? we long to discover ________________ why we get tired ______________

47. TL2 — Have you any idea why ? — How did it come about that ? — Is that the reason ? — How come ? — The reason why is that . — Well, you see, . — Well, the thing is, . — It’s (simply) because ! — Let me explain: . — Yes, you’re dead right. ____________ it is so difficult we got so much rain ________________ you got a cold ____________ it happens that way _______________ Pick up the following sentences to give reasons: _____________________ we have different seasons __________________________ the earth moves around the sun discovery is exciting _________________ the body needs to rest __________________ __________ it takes time it was the rainy season __________________

48. TL3 — The weather has much to do with making it happen. — The credit goes to . — Well, this is the beginning of the story. — Well, this is part of the story. — Yes, this is the whole story. — The reason is…. physical exercise ______________ Now raise as many questions as possible in class and see whether there are answers to them. Try to use the language picked up in Exercise 1.

49. appetite 食欲 the latter后者 the former前者 put on weight 增加体重 unique 独特的 gene 基因 CP-gtn1 Asking For and Giving Reasons • Before you listen to the first conversation, read the following words and expressions which may be new to you.

50. CP-gtn2 Listen to the following conversation twice and fill in the blanks with the missing words. __________ final exams Wang Ying:How come I tend to lose my appetite before the ? Li Ming:Well, , you’re under a lot of pressure right now. Wang Ying:Yes, you’re . I’m pretty stressed out. Li Ming:I can tell. You know, people tend to overeat or eat little . Wang Ying:Are you trying to say I the latter? Li Ming:I think so. Wang Ying:Which group do you belong to? Li Ming:Uh, maybe I belong to . Wang Ying: So you’re putting on weight while I’m losing it these days? the thing is _________ dead right _________ under stress __________ belong to ________ the former ________ Why is that? __________