Passage 2 Birds that are literally half asleep—with one brain hemisphere alert and the other sleeping—control which side of the brain remains awake, according to a new study of sleeping ducks. Earlier studies have documented half brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once. Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end of the row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction. Also, birds dozing at the end of the line resorted to single hemisphere sleep, rather than total relaxation, more often than inner ducks did. Rotating 16 birds through the positions in a four duck row, the researchers found outer birds half asleep during some 32 percent of dozing time versus about 12 percent for birds in internal spots. “We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously in different regions of the brain,” the researchers say. The results provide the best evidence for a long standing supposition that single hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread, he predicts. He’s seen it in a pair of birds dozing side by side in the zoo and in a single pet bird sleeping by a mirror. The mirror side eye closed as if the reflection were a companion and the other eye stayed open. Useful as half sleeping might be, it’s only been found in birds and such water mammals as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning. Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds’ half brain sleep “is just the tip of the iceberg (冰山)” He speculates that more examples may turn up when we take a closer look at other species.
A new study on birds’ sleep has revealed that ________. A) half brain sleep is found in a wide variety of birds B) half brain sleep is characterized by slow brain waves C) birds can control their half brain sleep consciously D) birds seldom sleep with the whole of their brain at rest
ID：9121-12944 If a person talks about his weak points, his listener is expected to say something in the way of ________. A) persuasion B) remedy C) encouragement D) compromise
ID：9121-11847 A transformation is occurring that should greatly __1__ living standards in the developing world. Places that __2__ recently were deaf and dumb are rapidly acquiring __3__ telecommunications. Many developing countries are planning to invest vast sums of money __4__ their telecommunications networks to allow them to __5__ with developed countries. They believe this will __6__ foreign and domestic investment. However, how fast these nations should push __7__ is a matter of debate. And some developing countries __8__ experience in weighing costs and choosing between technologies. Vietnam, __9__ particular, though desperate for any phones, requires that all mobile phones be expensive digital models. Still, there is __10__ dispute that communications will be a key factor __11__ the winners from the losers. Over the next decade, China plans to pour some $100 billion into telecommunications equipment. Telecommunications is also a key __12__ Shanghai’s ambition of becoming a top financial center. Shanghai plans to be as electronically advanced __13__ New York. __14__, some other developing countries and areas such as Hungary, Latin America, and Thailand are all hoping to jump into the modern world __15__ means of telecommunication revolution. For countries that have lagged __16__ for so long, the temptation to move ahead in one jump is hard to __17__. And __18__ the mistakes they’ll make, they’ll persist ―__19__ day they can cruise alongside Americans and Western Europeans __20__ the information superhighway. 19 A so that B by then C while D when
ID：9121-12373（本题为引用材料试题，请根据材料回答以下问题） According to the passage, to combat the flu effectively, ________. A. one should identify the virus which causes it B. one should consult a doctor as soon as possible C. one should take medicine upon catching the disease D. one should remain alert when the disease is spreading
