题目内容
Passage TwoSome years ago industries had more freedom than they have now, and they did not need to be as careful as they must today. They did not need to worry a lot about the safety of the new products that they developed. They did not have to pay much attention to the health and safety of the people who worked for them. Often new products were dangerous for the people who used them; often conditions in the work place had very bad effects on the health of the workers.Of course sometimes there were real disasters which attracted the attention of governments and which showed need for changes. Also scientists who were doing research into the health of workers sometimes produced information which governments could not ignore. At such times, there were inquiries into the causes of the disaster or the problems. New safety rules were often introduced as a result of these inquiries; however, the new rule; came too late to protect the people who died or who became seriously ill.Today many governments have special departments which protect customers and workers. In the U.S., for example, there is a department which tests new airplanes and gives warnings about possible problems. It also makes the rules that aircraft producers must follow. Another department controls the foods and drugs that companies sell. A third department looks at the places where people work, and then reports any companies that are breaking laws which protect the health and safety of workers. Of course, new government departments and new laws cannot prevent every accident or illness, but they are having some good results. Our work places are safer and cleaner than before. The planes and cars which we use for travel are better. Producers are thinking more about the safety and health of the people who buy and use their products. The main topic of the passage is （）
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《神农本草经》的考订、整理、辑复、兴盛于
下列成员变量声明中，正确的是______。
Passage One"A rolling stone gathers no moss (苔藓) ," but there is one living animal that does gather moss, the three-toed sloth (树獭) 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 per- fect 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(多汁的值物). 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! Which of the following is NOT true about the sloth （）
Passage FiveAlthough no one is certain why migration occurs, there are several theories. One theory is based upon the premise that prehistoric birds of the northen Hemisphere were forced south during the Ice Age, when glaciers covered large parts of Europe, Asia, and North America. As the glaciers melted, the birds came back to their homelands, spent the summer, and then went south again as the ice advanced in winter. In time, the migration became a habit, and now, although the glaciers have disappeared, the habit continues.Another theory proposes that the ancestral home of all modern birds was the tropics. When the region became overpopulated, many species were crowded north. During the summer, there was plenty of food, but during the winter, scarcity forced them to return to the tropics.A more recent theory, known as photoperiodism, suggests a relationship between increasing daylight and the stimulation of certain glands in the birds’ bodies that may prepare them for migration. One scientist has been able to cause midwinter migrations by exposing birds to artificial periods of daylight. He has concluded that changes occur in the bodies of birds due to seasonal changes in the length of daylight. According to the theory of photoperiodism, （）
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