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Passage 37 Why don’t birds get lost on their long flights from one place to another Scientists have been puzzled over this question for many years. Now they’re beginning to fill in the blanks. Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly by night (37) Tests with artificial stars have proved that certain night-flying birds are able to follow the stars in their long-distance flights. A dove had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The bird’s cage was placed under an artificial star-filled sky. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the artificial stars caused a change in the direction of his flight. The stars are apparently their principal means of navigation. When the stars are hidden by clouds, they seemingly find their way by such landmarks as mountain ranges, coast lines, and river courses. But when it’s too dark to see these, the doves circle helplessly, unable to find their way. The experiment with the dove indicated that______.
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Passage 30 Elephants are the biggest animals that live on land (some whales are bigger than elephants but whales live in the sea), when born a baby elephant weighs 91 kilograms. That is the weight of a grown man. It is about 91 centimeters high. When it reaches the age of six years, it is about 183 centimeters high. (30) When it reaches the age of twelve years, it does not grow any more. It may then be 320 centimeters high. African elephants are bigger than Indian elephants. African elephants have much bigger ears. Elephants have very long noses which we call "trunks". No other animals have trunks as long as elephants. An elephant can use its trunk to smell things and it can also pick up things with the tip of its trunk. The tip of its trunk can be used like a hand. An elephant uses its trunk to feed itself. It likes to eat leaves, young juicy branches of a tree and fruit. It picks these with its trunk and puts the food into its mouth. When it wants a drink, it puts the tip of its trunk into water. It fills its trunk with water and then blows the water into the mouth. The elephant washes itself in the same way. It fills its trunk with water and then blows the water over itself. Two of the elephant’s teeth are very long and strong. They are called "tusks". They use their tusks to dig up small trees and to dig in the ground for water. Elephants also use their tusks to lift heavy logs of wood. In some countries men catch wild elephants and teach them to work. After a while they are no longer wild. They become tame. They become very obedient. They do what their masters tell them to do. All day long they work patiently in the hot sun. They pull trees along and lift heavy logs. No animal is stronger than an elephant. Elephants have very strong legs. Their legs are like trees. They usually walk slowly because they are so big, but they walk very quietly. An elephant uses its tusks for______.
Passage 24 The Chinese have used a method called acupuncture (针灸) to perform operations for about 4,000 years without putting the patient to sleep. This involves placing flexible needles into certain parts of the body. The needles are available in a number of stores in China and anyone may buy them. To learn how to use the needles takes about one month of training. But to be skillful requires greater time. The person who performs the acupuncture knows how to put in the needles so the needles themselves are not painful. This person also knows where to place the needles so the patient feels no pain in the area where the operation is to be performed. A particular operation might require 25 or more needles placed in various parts of the body. But now this operation requires only 3 or 4 needles. Today, the Chinese doctors are trying to learn more about acupuncture. (24) They are trying to develop a convincing theory to explain how the needles work in preventing pain, or why a needle in the wrist, for example, would prevent the pain in the area of the mouth. A patient who needs an operation is given a choice between having acupuncture or having one of the chemicals used for putting him to sleep. It has been estimated that over half of the patients choose acupuncture because there is no sickness after the operation because the chemical may make the patient sick for a few hours or a day. It can be learned form the passage that______.
Passage 34 Americans and Arabs are different in their space habits. Arabs prefer close contact.Dr. Hall has explained that the Arabs belong to a touch culture and in conversation, they always envelop the other person. They hold his hand, look into his eyes, and bathe him in their breath. Dr. Hall’s interest in man’s use of space developed in the early nineteen fifties when he was Director of the Point Four training program at the Foreign Service Institute. In talking with Americans who had lived overseas, he found that many of them had been highly uncomfortable because of cultural differences. Such discomfort is usually referred to as culture shock. The problem is that, relatively speaking, Americans live in a non-contact culture. Partly, this is a product of our puritan heritage (清教徒文化遗产). Dr. Hall points out that we spend years teaching our children not to crowd in and lean on us. (34) And in situations where we ourselves are forced to stand close to another person on crowded subways, for example, we turn our eyes away, and if actual body contact is involved, tense the muscles on the contact side. Most of us feel very strongly that this is the only proper way to behave. Which of the following is NOT mentioned in the passage
Passage 43 Sometimes it is impossible to send all the mail that arrives at the post office. Perhaps there is an inadequate or illegible address and there is no return address. The post office cannot just throw the mail away, so it becomes "dead mail". Dead mail is then sent to one of the U.S. Postal Service’s dead mail offices in Atlanta, New York, Philadelphia, St. Paul, and San Francisco. Seventy-five million pieces of mail can end up in these offices in one year. The staff ’of the dead mail offices has different ways to deal with all of these pieces of dead mail. First of all, they look for clues that can help them deliver the mail; they open packages in the hope that something inside will show where the package came from or is going to. (43) Dead mail will also be listed on a computer so that people can call in and cheek to see if a missing item is there. However, all of the mail cannot simply be stored forever: there is just too much of it. When a lot of dead mail has piled up, the dead mail offices hold public auctions. Every three months, the public is invited to the offices and containing items found in dead mail packages are sold to the highest bidder (出价人). The passage indicates that dead mail auctions are held______.
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