单选题"A roiling stone gathers no moss (苔藓)," but there is one living animal that does gather moss, the three-toed sloth (树懒) of South America. This slowest-moving member of the animal kingdom is so inactive that moss actually gathers on its body and turns it green—strange as it seems! Most of the sloth"s life is spent motionless, hanging upside down from a limb. And that is the way its hair grows. Long and coarse, the strands (串) from receptacles (花托) for the damp jungle algae (水藻) that turn the brown fur a mossy green. Actually this moss helps the animal survive because it serves as a perfect camouflage against the leaf trees and hides the sloth from the jungle"s swift-moving hunters. The sloth would have little chance of survival on the ground. With long, curved claws hooked over the limb of a leafy tree, it spends the long hot hours during the day drowsing and eating. Inch by inch, it strips the leafy limbs bare and crawls slowly down the trunk to find a new dining spot, but only at night. In addition to looking rather like a vegetable, the sloth is a strict vegetarian. Running out of its favorite leaf is about the only thing that will make a sloth move. Then its appetite may even force the animal into swimming a stream to reach a juicy succulent (多汁的植物). It will also force it into fighting to keep the tree all to itself. The sloth is lazy and prefers to be alone, but it will tolerate its own relatives!

单选题 (21) summary of the physical and chemical (22) of life must begin, not on the Earth, but (23) the Sun; in fact, (24) the Sun's very center. (25) is here that is to be found the (26) of the energy that the Sun constantly (27) space (28) light and heat. This energy is liberated at the center of the Sun as billions upon billions of nuclei hydrogen atoms (29) each other and (30) to form nuclei of helium, and, (31) doing so, (32) some of the energy that is stored in the nuclei of atoms. The output of light and heat of the Sun (33) that some 600 million tons of hydrogen (34) helium in the Sun every second. This the Sun (35) for several thousands of millions of years.

单选题The destruction of our natural resources and contamination of our food supply continue to occur, largely because of the extreme difficulty in affixing (把……固定) legal responsibility on those who continue to treat our environment with reckless abandon (放任). Attempts to prevent pollution by legislation, economic incentives and friendly persuasion have been met by lawsuits, personal and industrial denial and long delays—not only in accepting responsibility, but more importantly, in doing something about it. It seems that only when government decides it can afford tax incentives or production sacrifices is there any initiative for change. Where is industry's and our recognition that protecting mankind's great treasure is the single most important responsibility? If ever there will be time for environmental health professionals to come to the frontlines and provide leadership to solve environmental problems, that time is now. We are being asked, and, in fact, the public is demanding that we take positive action. It is our responsibility as professionals in environmental health to make the difference. Yes, the ecologists, the environmental activists and the conservationists serve to communicate, stimulate thinking and promote behavioral change. However, it is those of us who are paid to make the decisions to develop, improve and enforce environmental standards, I submit, who must lead the charge. We must recognize that environmental health issues do not stop at city limits, county lines, state or even federal boundaries. We can no longer afford to be tunnel-visioned in our approach. We must visualize issues from every perspective to make the objective decisions. We must express our views clearly to prevent media distortion and public confusion. I believe we have a three-part mission for the present. First, we must continue to press for improvements in the quality of life that people can make for themselves. Second, we must investigate and understand the link between environment and health. Third, we must be able to communicate technical information in a form that citizens can understand. If we can accomplish these three goals in this decade, maybe we can finally stop environmental degradation, and not merely hold it back. We will then be able to spend pollution dollars truly on prevention rather than on bandages.

单选题His constructive proposal for improving the program is ______of our attention.

单选题Children who are described as mildly mentally mentally handicapped are often upset to hear themselves described as such, and such terms as "children with learning difficulties" are now ______.

单选题For the first time, we found______ that allow us to connect the first phase of human evolution and the second phase. A. theories B. morasses C. frescos D. fossils

单选题A: May I see the dentist now? B: ______ A. Is it a real emergency? B. Do you have an appointment? C. In that case, you'll have to wait. D. I'll talk to the dentist and squeeze you in.

单选题The question of salary increase will ______ at the next general meeting. A. come off B. come up C. come to D. come through

单选题(Despite of) the Taft-Hartley Act which (forbids) unfair union practices, some unions (such as)the air traffic controllers have voted (to strike) even though it might endanger the national security.A. Despite ofB. forbidsC. such asD. to strike

单选题The appeal of advertising to buying motives can have both negative and positive effects. Consumers may be convinced to buy a product of poor quality or high price because of an advertisement. For example, some advertisers have appealed to people's desire for better fuel economy for their cars by advertising automotive products that improve gasoline mileage. Some of the products work. Others are worthless and a waste of consumers' money. Sometimes advertising is intentionally misleading. A few years ago a brand of bread was offered to dieters with the message that there were fewer calories in every slice. It turned out that the bread was not dietetic (适合于节食的), but just regular bread. There were fewer calories because it was sliced very thin, but there were the same number of calories in every loaf. On the positive side, emotional appeals may respond to a consumer's real concerns. Consider fire insurance. Fire insurance may be sold by appealing to fear of loss. But fear of loss is the real reason for fire insurance. The security of knowing that property is protected by insurance makes the purchase of fire insurance a worthwhile investment for most people. If consumers consider the quality of the insurance plans as well as the message in the ads, they will benefit from the advertising. Each consumer must evaluate her or his own situation. Are the benefits of the product important enough to justify buying it? Advertising is intended to appeal to consumers, but it does not force them to buy the product. Consumers still control the final buying decision.

单选题{{B}} Directions: For each blank in the following passage, choose the best answer from the choices givenbelow. Mark your answer on the ANSWER SHEET by drawing with a pencil a short bar acrossthe corresponding letter in the brackets.{{/B}} Educational attitudes in a country may be a{{U}} 31 {{/U}}by which its basic cultural values arereflected. To take the American higher education{{U}} 32 {{/U}}example, university classrooms sharecertain identical features though they{{U}} 33 {{/U}}from course to course in some aspects. Any student,{{U}} 34 {{/U}}their ethnic and social background, is not only allowed hut also encouraged to have chancesfor active participation in class.{{U}} 35 {{/U}}, teachers often expect independent learning{{U}} 36 {{/U}}theirstudents. It will be most appreciated if a student can{{U}} 37 {{/U}}the initiative and complete theassignment without too much{{U}} 38 {{/U}}upon his or her instructors. These two{{U}} 39 {{/U}}features inAmerican university classrooms actually manifest the basic American values, especiallyself-reliance and{{U}} 40 {{/U}}of opportunity.

单选题The mayor is a woman with great ______ therefore deserves our political and financial support.

单选题Man: How did you go to Canada, Jane? Did you fly? Woman: I was planning to, because it's such a long trip by bus or by train. But Fred decided to drive and invited me to join him. It took us two days and a night. Question: What can we infer from the conversation? A. Fred is planning a trip to Canada. B. Fred usually flies to Canada with Jane. C. Fred persuaded Jane to change her mind. D. Fred likes the beautiful scenery along the way to Canada.

单选题Jenny is the only one of the grade who ______selected to school fashion-show team

单选题 It is curious to note how slowly the mechanism of the intellectual life improves. Contrast the ordinary library facilities of a middle-class English home, such as the present writer is now working in, with the inconveniences and deficiencies of the equipment of an Alexandrian writer, and one realizes the enormous waste of time, physical exertion, and attention that went on through all the centuries during which that library flourished. Before the present writer lie half a dozen books, and there are good indices to three of them. He can pick up any one of these six books, refer quickly to a statement, verify a quotation, and go on writing. Contrast with the tedious un- folding of a rolled manuscript. Close at hand are two encyclopedias, a dictionary, an atlas of the world, a biographical dictionary, and other books of reference. They have no marginal indices, it is true, but that, perhaps, is asking too much at present. There were no such resources in the world in 300 B.C. Alexandria had still to produce the first grammar and the first dictionary. This present book is being written in manuscript; it is then taken by a typist and typewritten very accurately. It can then, with the utmost convenience, be read over, corrected amply, rearranged freely, retyped, and recorrected. The Alexandrian author had to dictate or recopy every word he wrote. Before he could turn back to what he had written previously, he had to dry his last words by waving them in the air or pouring sand over them; he had not even blotting-paper. Whatever an author wrote had to be recopied again and again before it could reach any considerable circle of readers, and every copyist introduced some new error. New books were dictated to a roomful of copyists, and so issued in a first edition of some hundreds at least. In Rome, Horace and Virgil seem to have been issued in quite considerable editions. Whenever a need for maps or diagrams arose, there were fresh difficulties. Such a science as anatomy, for example, depending as it does upon accurate drawing, must have been enormously hampered by the natural limitations of the copyist. The transmission of geographical fact again must have been almost incredibly tedious. No doubt a day will come when a private library and writing desk of the year A.D. 1925 will seem quaintly clumsy and difficult; but, measured by the standards of Alexandria, they are astonishingly quick, efficient, and economical of nervous and mental energy.

单选题California is a land of variety and contrast. Almost every type of physical land feature, sort of arctic ice fields and tropical jungles can be found within its borders. Sharply contrasting types of land often lie very close to one another. People living in Bakersfield, for instance, can visit the Pacific Ocean and the coastal plain, the fertile San Joaquin Valley, the arid Mojave Desert, and the high Sierra Nevada, all within a radius of about 100 miles. In other areas it is possible to go snow skiing in the morning and surfing in the evening of the same day, without having to travel long distance. Contrast abounds in California. The highest point in the United States(outside Alaska)is in California, and so is the lowest point(including Alaska). Mount Whitney, 14,494 feet above sea level, is separated from Death Valley, 282 feet below sea level, by a distance of only 100 miles. The two areas have a difference in altitude of almost three miles. California has deep, clear mountain lakes like Lake Tahoe, the deepest in the country, but it also has shallow, salty desert lakes. It has Lake Tulainyo, 12,020 feet above sea level, and the lowest lake in the country, the Saltan Sea, 236 feet below sea level. Some of its lakes, like Owens Lake in Death Valley, are not lakes at all: they are dried up lake beds. In addition to mountains, lakes, valleys, deserts, and plateaus, California has its Pacific coastline, stretching longer than the coastlines of Oregon and Washington combined.

单选题(2004)She has got a chair____.

单选题You can' t go that way, I' m afraid, as the road is ______ repair.

单选题______ preparations were being made for the Prime Minister's official visit to the four universities.

单选题It is difficult to discern the sample that is on the slide unless the microscope is adjusted properly. A. overlook B. disclaim C. discard D. detect