Science textbooks and technical and professional journals are usually made up of several parts and contain various special features, many of which have a standard format.【B1】usually contain a large number of these parts; journals and【B2】contain many, but not all of them. Knowing where to look for information and【B3】to expect in a book can greatly increase your ability to use all the information there. Explanations of and practice using some of these textbook parts and【B4】are covered in these even numbered lessons. The features in textbooks are【B5】into the following three categories. Front matter is the【B6】-numeral paginated section at the front of most books. The text is the main body of the book. The【B7】matter comprises the additional sections at the back of most books.【B8】our discussion of these three sections will deal mainly with textbooks, the practice provided will greatly【B9】your comprehension of scientific【B10】as well.

For an increasing number of students at American universities, Old is suddenly in. The reason is obvious: the graying of America means jobs. Coupled with the aging of the baby-boom(生育高峰) generation, a longer life span means that the nation"s elderly population is bound to expand significantly over the next 40 years. By 2040, 25 percent of all Americans will be older than 65, up from 14 percent in 1995. The change poses profound questions for government and society, of course. But it also creates career opportunities in medicine and health professions, and in law and business as well. "In addition to the doctors, we"re going to need more sociologists, biologists, urban planners and specialized lawyers". says Professor Edward Schneider of the University of Southern California"s (USC), School of Gerontology (老年学). Lawyers can specialize in "elder law", which covers everything from trusts and estates to nursing-home abuse and age discrimination(歧视). Businessmen see huge opportunities in the elder market because the baby boomers, 74 million strong, are likely to be the wealthiest group of retirees in human history. "Any student who combines an expert knowledge in gerontology with, say, an MBA or law degree will have a license to print money", one professor says. Margarite Santos is a 21-year-old senior at USC. She began college as a biology major but found she was "really bored with bacteria". So she took a class in gerontology and discovered that she liked it. She says, "I did volunteer work in retirement homes and it was very satisfying".

The first ancient Olympics were held in 776 B.C. The games got their name from Olympia, the Greek city where they took place. Like the summer Olympics of today, the ancient Olympics were held every four years. Thousands of people from all over the Greek world came to watch. The main stadium held about 45,000 people. "We have accounts of visitors and pilgrims setting up tents all around the site", Lisa Cerrato of Tufts University said. During the first Olympics, there was only one competition—a 200-meter race. But over time the games grew to include wrestling, chariot racing, boxing, and other sports. Women were not allowed to compete, but they had their own separate games. "The ancient athlete became celebrities(名人), just like today. They often lived the rest of their lives being treated to free dinners", Cerrato said. "City-states even tried to steal away each other"s athletes by offering them various awards". The ancient Olympics existed until A.D. 393. But the modem Olympics are still going strong.

Teacher; Richard, class begins at 9, and you are late. Student: I know, but I missed my bus. I"m sorry. Teacher; ______. You have to be here on time.

The coat I"m wearing now costs about ______ of that one hung over there.

Double Income and No Kids(DINK) becomes fashionable in China. The DINK couples are usually regarded as those who have higher educations and【B1】careers with higher incomes. The increase in DINK families has shattered the Chinese traditional idea of the family and【B2】typical. A survey conducted recently in Beijing by a market survey company【B3】that about 3.8 percent of 1,300 surveyed families in Beijing said they have【B4】plans to have children. It is estimated there are about 600,000 DINK families in large cities like Beijing, Tianjin, Shanghai, and Chongqing. Why they choose such a lifestyle is concluded in【B5】reasons. Some are showing great worry for the rapid growth of population; some are indulged in building a more well-off family; some are showing sharp【B6】to get themselves free from the obligation of raising children. 【B7】, most people still believe it is necessary to bear a child to keep the family line on. As an old Chinese saying goes, there are three aspects in failing to be a filial son and the【B8】serious one is to have no heir for the family. So childless couples will suffer discrimination【B9】family members and neighbors. But it is clear that the new tide of ideas has come, which suggests young people【B10】to choose their own way of life They are installing modem ideas into traditional families and society. In the modernization process, personal choices will be highly respected.

Vitamins are organic compounds necessary in small amounts in the diet for the normal growth and maintenance of life of animals, including man. They do not provide energy,【B1】do they construct or build any part of the body. They are needed for【B2】foods into energy and body maintenance. There are thirteen or more of them, and if【B3】is missing a deficiency disease becomes【B4】. Vitamins are similar because they are made of the same elements—usually carbon, hydrogen, oxygen, and【B5】nitrogen. They are different【B6】their elements are arranged differently, and each vitamin【B7】one or more specific functions in the body.【B8】enough vitamins is essential to life, although the body has no nutritional use for【B9】vitamins. Many people,【B10】, believe in being on the "safe side" and thus take extra vitamins. However, a well-balanced diet will usually meet all the body"s vitamin needs.

Speaker A: We"ve made an appointment with the students. We"ll meet at 7 in the morning. Can you come on time? Speaker B: I"m afraid ______. It"s too early.

Jane: ______ Tom: Well, it"s 250 dollars a month, including heat.

One thing almost everyone is agreed on, including Americans, is that they place a very high valuation upon success; Success does not necessarily mean material rewards, but recognition of some sort-preferably measurable. If a boy turns out to be a preacher(传道者) instead of a businessman, that"s all right. But the bigger his church is, the more successful he is judged to be. A good many things contributed to this accent on success. There was the Puritan(清教徒的) belief in the virtue of work, both for its own sake and because the rewards it brought were regarded as signs of God"s love. There was the richness of opportunity in a land waiting to be settled. There was the lack of a settled society with fixed ranks and classes, so that a man was certain to rise through achievement. There was the determination of an immigrant to gain in the new world what had been denied to him in the old, and on the part of his children an urge to throw off the immigrant onus(负担) by still more success and still more rise in a fluid and classless society. Brothers did not compete within the family for the favor of the parents as in Europe, but worked hard for success in the outer world, along paths of their own choosing.

A mother dolphin(海豚) chats with her baby over the telephone! They were in separate tanks connected by a special underwater audio link. "It seemed clear that they knew who they were talking with", says Don White, whose Project Delphis ran the experiment. But what were they saying? Scientists think dolphins "talk" about everything from basic facts like their age to their emotional state. "I speculate that they say things like "there are some good fish over here," or "watch out for that shark because he"s hunting,"" says Denis Herzing, who studies dolphins in the Bahamas. Deciphering(译解) "dolphin speak" is also tricky because their language is so dependent on what they"re doing, whether they"re playing, fighting, or going after tasty fish. During fights, for example, dolphins clap(碰撞) their jaws to say "Back off!" But their jaws clap while playing, too, as if to show who"s king of the underwater playground.

Robert: Mary, I"d like you to meet my new neighbor, Tom. Mary: Hello, Tom. It"s nice to meet you.Tom: ______

A: This chocolate is delicious! Thanks for bringing me here. B: ______. Each time I try a new flavor, it becomes my favorite.

Engineering students are supposed to be examples of practicality and rationality, but when it comes to my college education I am an idealist and a fool. In high school I wanted to be an electrical engineer and, of course, any sensible student with my aims would have chosen a college with a large engineering department, famous reputation and lots of good labs and research equipment. But that"s not what I did. I chose to study engineering at a small liberal-arts(文科) university that doesn"t even offer a major in electrical engineering. Obviously, this was not a practical choice; I came here for more noble reasons. I wanted a broad education that would provide me with flexibility and a value system to guide me in my career. I wanted to open my eyes and expand my vision by interacting with people who weren"t studying science or engineering. My parents, teachers and other adults praised me for such a sensible choice. They told me I was wise and mature beyond my 18 years, and I believed them. I headed off to college sure I was going to have an advantage over those students who went to big engineering "factories" where they didn"t care if you had values or were flexible. I was going to be a complete engineer: technical genius and sensitive humanist(人文学者)all in one. Now I"m not so sure. Somewhere along the way my noble ideals crashed into reality, as all noble ideals eventually do. After three years of struggling to balance math, physics and engineering courses with liberal-arts courses, I have learned there are reasons why few engineering students try to reconcile(协调) engineering with liberal-arts courses in college. The reality that has blocked my path to becoming the typical successful student is that engineering and the liberal arts simply don"t mix as easily as I assumed in high school. Individually they shape a person in very different ways; together they threaten to confuse. The struggle to reconcile the two fields of study is difficult.

The architectural differences may ______ confusion or discomfort for the foreign travelers.

Hurricanes are violent storms that cause millions of dollars in property damage and take many lives. They can be extremely dangerous, and too often people underestimate their fury. Hurricanes normally originate as a small area of thunderstorms over the Atlantic Ocean west of the Cape Verde Islands during August or September. For several days, the area of the storm increases and the air pressure falls slowly. A center of low pressure forms, and winds begin to whirl around it. It is blown westward, increasing in size and strength. Hurricane hunters then fly out to the storm in order to determine its size and intensity and to track its direction. They drop instruments for recording temperature, air pressure, and humidity(湿度), into the storm. They also look at the size of waves on the ocean, the clouds, and the eye of the storm. The eye is a region of relative calm and clear skies in the center of the hurricane. People often lose their lives by leaving shelter when the eye has arrived, only to be caught in tremendous winds again when the eye has passed. Once the forecasters have determined that it is likely the hurricane will reach shore, they issue a hurricane watch for a large, general area that may be in the path of the storm. Later, when the probable point of landfall is clearer, they will issue a hurricane warning for a somewhat more limited area. People in these areas are wise to stock up on nonperishable foods, flash light and radio batteries, candles, and other items they may need if electricity and water are not available after the stoma. They should also try to hurricane-proof their houses by bringing in light-weight furniture and other items from outside and covering windows. People living in low-lying areas are wise to evacuate their houses because of the storm surge, which is a large rush of water that may come ashore with the storm. Hurricanes generally lose power slowly while traveling over land, but many move out to sea, gather up force again, and return to land. As they move toward the north, they generally lose their identity as hurricanes.

Speaker A: Why do you always tell me what to do? To be frank, I don"t like it. Speaker B: I know, but______

No reference book, perhaps no book of any kind except the Bible, is so widely used as "the dictionary". Even houses that have few books or none at all possess at least one dictionary; most business offices have dictionaries, and most typists keep a copy on their desks; at one time or another most girls and boys are required by their teachers to obtain and use a dictionary. Admittedly, the dictionary is often used merely to determine the correct spelling of words, or to find out the accepted pronunciation, and such a use is perhaps not the most important from an intellectual point of view. Dictionaries may, however, have social importance, for it is often a matter of some concern to the person using the dictionary for such purpose that he should not suggest to others, by misspelling a word in a letter, or mispronouncing it in conversation, that he is not "well-bred", and has not been well educated. Yet, despite this familiarity with the dictionary, the average person is likely to have many wrong ideas about it, and little idea of how to use it profitably, or interpret it rightly. For example, it is often believed that the mere presence of a word in a dictionary is evidence that it is acceptable in good writing. Though most dictionaries have a system of marking words as obsolete, or in use only as slang, many people, more especially if their use of a particular word has been challenged, are likely to conclude, if they find it in a dictionary, that it is accepted as being used by writers of established reputation. This would certainly have been true of dictionaries a hundred years or so ago. For a long time after they were first firmly established in the eighteenth century, their aim was to include only what was used by the best writers, and all else was suppressed, and the compiler frequently claimed that this dictionary contained "low" words. Apparently this aspect of the dictionary achieved such importance in the mind of the average person that most people today are unaware of the great change that has taken place in the compilation of present-day dictionaries. Similarly, the ordinary man invariably supposes that one dictionary is as good and authoritative as another, and, moreover, believes that "the dictionary" has absolute authority, and quotes it to clinch arguments. Although this is an advantage, in that the dictionary presents a definition the basic meaning of which can"t be altered by the speaker, yet it could be accepted only if all dictionaries agreed on the particular point in question. But ultimately the authority of the dictionary rests only on the authority of the man who compiled it, and, however careful he may be, a dictionary-maker is fallible: reputable dictionaries may disagree in their judgments, and indeed different sections of the same dictionary may differ.

Color is very important to most animals for it helps them to get along in the world. Color【B1】to make an animal difficult for its enemies to see. Many animals match their【B2】so well that as long as they do not move no one is【B3】to see them. You probably have often "jumped" a rabbit. If you【B4】, you know how the rabbit sits perfectly still【B5】you are just a few feet away. You【B6】see the rabbit till it runs for its【B7】matches very closely the place where it is【B8】Many times you may have walked past a rabbit【B9】didn"t run and you never knew it was there at all. One of the most usual color schemes that helps animals to keep【B10】being seen, is a dark back and light underpants, if an animal is the same color all over, there is always a dark shadow along the animal"s belly(腹部). Even if an enemy couldn"t see the animal he could see this dark shadow.

People appreciate ______ with him because lie has a good sense of humor.