How Animals Keep Warm
Man has invented ways to keep warm, but how do animals defend themselves? They cannot reason in the sense that man can, but nature has taken care of the animal kingdom by providing animals with special instincts （本能）. One of these instincts is known as hibernation （冬眠）.
"Sleeping like a dormouse （榛睡鼠）" is not only a common saying but is a reality. When winter comes, the dormouse and other hibernating animals have reached a well-nourished state. They eat very well in warmer days laying down fat in the tissues of their bodies and during hibernation this keeps them alive. Safe in their nests, or burrows （地洞）, they sleep soundly until the warmth of spring arrives.
Bats, tortoises, snakes, frogs, even insects like butterflies, hibernate more or less completely. Some, like the squirrels （松鼠）, sleep during coldest weather but are roused （弄醒） by a warm spell （暖流）. During hibernation, the temperature of an animal's body drops drastically. Breathing and heart-beats almost cease.
Another instinctive method of avoiding intense cold is to escape by means of migration. Wild swans, seagulls, swallows and cuckoos are a few of the very many kinds of birds which fly thousands of miles, twice a year, to avoid cold. Many animals, especially those of the Arctic regions, have summer and winter quarters. The Arctic deer of North America, as well as the reindeer （驯鹿） of Europe, move southward towards the forests when winter approaches. They return to the northern area when the warmth of spring begins to be sensed.
There are animals which do not attempt to leave at the first sign of winter cold. Their instinctive means of defense is to dig out a deep burrow, made it soft and warm by padding （填塞） out with straw, leaves, moss and fur. In it they have a "secret place" containing food which they hope will last the winter through! Animals which fall into this class include the Arctic fox, the rabbit and the little field-mouse.
1 How does the dormouse defend itself against cold in winter?
A It moves about to keep warm,
B It grows thicker fur.
C It stores fat before hibernation.
D It goes to warmer areas.
2 "Sleeping like a dormouse" most probably means
A sleeping longer on cold days.
B sleeping badly.
C sleeping with a lower heartbeat rate.
D sleeping with little breathing.
3 During hibernation, animals breathe
B at a slower rate.
C at a faster rate.
4 According to the passage, "migration" （paragraph 4） means
A moving from one place to another at a particular time of the year.
B living in burrows in winter.
C traveling in the winter months.
D visiting foreign countries.
5 How does the Arctic fox survive in winter?
A It leaves its burrow and migrates to a warmer land.
B It sleeps soundly inside its burrow in winter.
C It lives on rabbits or field mice.
D It stays in its burrow and lives on the food stored there.
Sleep Necessary for Memories
Burning the midnight oil before an exam or interview does harm to the performance according to a recent research which found that sleep is necessary for memories to be taken back into the brain. A good night's sleep within 30 hours of trying to remember a new task is a required condition of having good recall in the weeks ahead, scientists have found.
The research, published in the December issue of Nature Neuroscience, showed that it was the act of sleep, rather than the simple passage of time, that was critical for long-term memory formation.
"We think that getting that first night's sleep starts the process of memory consolidation （巩固）," said Robert Stickgold, a sleep researcher at Harvard Medical School who conducted the latest study.
It seems that memories normally wash out of the brain unless some process nails them down. My suspicion is that sleep is one of those things that does the nailing down," Professor Stickgold said.
With about one in five people claiming that they are so chronically short of sleep that it affects their daily activities, the latest work emphasizes the less well-understood side effect - serious memory impairment （损害）.
Volunteers in an experiment found it easier to remember a memory task if they were allowed to sleep that night. But for those kept awake, no amount of subsequent sleep made up for the initial loss.
Professor Stickgold's team trained 24 people to identify the direction of three diagonal （斜线形的） bars flashed for a sixtieth of a second on a computer screen full of horizontal （水平的） stripes.
Half of the subjects were kept awake that night, while the others slept. Both groups were allowed to sleep for the second and third nights to make up for any differences in tiredness between the volunteers.
Those who slept the first night were significantly and consistently better at remembering the task while the second group showed no improvement despite enjoying two nights of catch-up sleep.
6 The research published in Nature Neuroscience showed that what was essential to the formation of long-term memory was
7 Which of the following statements about the research is NOT true?
A It was done within 30 hours.
B It was headed by Professor Stickgold.
C It focused on long-term memory formation.
D There were altogether 24 subjects in the experiment.
8 Stickgold's research focused on the side effect produced by
A memory impairment.
B lack of sleep.
C low work efficiency.
D memory recall.
9 In Stickgold's experiment, those who were kept awake on the first night
A could very well remember the direction of the diagonal bars.
B didn't do any better after two nights' sleep.
C were as tired as those who were not.
D could recall the direction of more bars than those who were not.
10 Those who slept the first night
A couldn't remember the task.
B could not sleep the second and third nights.
C performed slightly better than those who did not,
D did much better than those who did not.
TapeStore: A New Tape Storage System
TapeStore is a new kind of tape storage system which can store up to 6,000 computer tapes. No other tape storage system can hold as many computer tapes as TapeStore. The tapes look exactly like video cassettes. Many hundreds of data files can be stored on each tape, up to a maximum of 500 million bytes （字节） of data. If you stored the same amount of information on paper, you would "need nearly 4.5 billion printed pages.
The machine is a tall black box with a mechanical arm. The machine is 2.5 metres high and 3.0 metres wide. This is how it works. Each tape has a code printed on it. You feed the code number into TapeStore, which then looks for the code. As soon as TapeStore locates the code, the arm reaches in and pulls out the tape.
The system is very fast. It takes the mechanical arm about 10 seconds to find the tape it is looking for. The machine then searches the tape to extract （提取） the required file, and this takes less than a minute. A human technician would have to locate and remove the tape by hand, and could take at least an hour to find the right file on the tape.
Some of the world's biggest companies, including banks, insurance companies, airlines, telephone companies, utilities and computer centres, have bought the system.
They like it particularly because the system guarantees the security of their data.
TapeStore was originally developed in Canada and is now being marketed worldwide. In Europe alone, 750 have already been installed at a cost of 480,000 dollars each.
11 TapeStore is better than any other storage system because
A it can store more video cassettes.
B it is extremely small.
C it stores more tapes.
D it stores data files on the same tape.
12 The mechanical arm finds a tape by
A recording the file name on the tape.
B identifying the printed code on the tape
C looking for its file name.
D searching for the tape number.
13 The TapeStore system is popular among big companies mainly because
A it costs less than a skilled worker.
B it looks impressive.
C the information it stores is valuable.
D it ensures the safety of their data.
14 Which of the following statements about TapeStore is NOT true?
A It can store a large amount of information.
B It is very cheap.
C It is very fast.
D It is secure.
15 The word "marketed" in the last paragraph can be replaced by
1. C 2. A 3. B 4. A 5. D
6. D 7. A 8. B 9. B 10. D
11. C 12. B 13. D 14. B 15. C