二、阅读理解

　　As scientists learn more about the causes of earthquakes, they become better able to predict them. First of all, they know that quakes are likely to occur in areas where the tectonic plates(地层地壳板块)push against each other. They study these areas closely, using different instruments. They measure the vibrations of the earth with seismographs(地震仪), which record on rolls of paper all movements, both large and small. Scientists usually use the Richter scale(里希特震级仪)named after a famous seismologist(地震学家), for these measurements. When an earthquake measures over 4~5 on the Richter scale, it is strong enough to cause damage. Scientists have determined that an area is not likely to have a large earthquake when many small quakes have been occurring. When the small quakes stop, then pressure builds and a strong quake is more likely.

　　There are several other ways to predict earthquakes. Scientists can measure the tiny changes in the tilt(倾斜)of the land that happen before earthquakes occur. Increases in the amount of radon(氡), a substance found in deep wells, as well as a higher level of water in the wells, can also mean that an earthquake is likely to occur. In addition, scientists have found that some animals, like dogs, behave strangely before an earthquake, they become nervous and howl(号叫). Seismologists have correctly predicted several earthquakes. In 1975, they said that an earthquake would occur in Liaoning Province, China, one month, and then one hour, before it happened. In 1978, Russian scientists predicted an earthquake in the Altai Mountains six hours before it occurred. However, not all earthquakes are predictable, and a system for predicting is not yet perfected. Nothing on this earth is certain. Although people who live in California and Japan live with the possibility of a serious quake, perhaps the next strong earthquake will occur somewhere outside the "Ring of Fire".

　　11. According to the information in Para. 1 seismograph is ______.

　　A. a computer like electronic instrument for predicting earthquakes

　　B. a special instrument for recording and measuring the vibrations of the earth

　　C. an instrument which seismologists use to make studies on the causes of earthquakes

　　D. an instrument with which seismologists measure the pressure between tectonic plates

　　答案：B

　　12. According to the passage, a large earthquake is most likely to occur in an area ______.

　　A. where a series of minor vibrations of the earth have been occurring

　　B. that is within the "Ring of Fire" but does not see any vibration of the earth

　　C. where many small vibrations of the earth have been occurring and then a calm period follows

　　D. where tectonic plates fit into each other properly

　　答案：C

　　13. The following signs that show the coming of an earthquake are mentioned in the passage EXCEPT that ______.

　　A. the amount of radon in deep wells increases

　　B. the earth gives off flashes of light

　　C. the level of water in the wells rises

　　D. some animals become nervous and behave strangely

　　答案：B

　　14. According to the passage, the earthquake occurred in China's Liaoning Province in 1975 ______.

　　A. was twice predicted by seismologists

　　B. took all the people in the area by surprise

　　C. was followed by many small vibrations of the earth

　　D. was correctly predicted by Russian seismologists

　　答案：A

　　15. Which of the following statements is TRUE according to the passage?

　　A. Not all earthquakes are predictable although seismologists have correctly predicted some.

　　B. Seismology was fully developed now and earthquake prediction is always reliable.

　　C. No earthquake prediction is reliable since nothing on this earth is certain.

　　D. A system for predicting the earthquake is perfected, but prediction is not always correct.

　　答案：A

　　American society is not nap(午睡)friendly. In fact, says David Dinges, a sleep specialist at the University of Pennsylvanian School of Medicine, "There's even a prohibition against admitting we need sleep." Nobody wants to be caught napping or found asleep at work. To quote a proverb: "Some sleep five hours, nature requires seven, laziness nine and wickedness eleven."

　　Wrong. The way not to fall asleep at work is to take naps when you need them. "We have to totally change our attitude toward napping," says Dr. William Dement of Stanford University, the godfather of sleep research.

　　Last year a national commission led by Dement identified an "American sleep debt" which one member said was as important as the national debt. The commission was concerned about the dangers of sleepiness: people causing industrial accidents or falling asleep while driving. This may be why we have a new sleep policy in the White House. According to recent reports, President Clinton is trying to take a half hour snooze(打瞌睡)every afternoon.

　　About 60% of American adults nap when given the opportunity. We seem to have "a mid afternoon quiet phase" also called "a secondary sleep gate." Sleeping 15 minutes to 2 hours in the early afternoon can reduce stress and make us refreshed. Clearly, we were born to nap.

　　We Superstar of Snooze don't nap to replace lost shut eye or to prepare for a night shift. Rather, we "snack" on sleep, whenever, wherever and at whatever time we feel like it. I myself have napped in buses, cars, planes and boats; on floors and beds; and in libraries, offices and museums.

　　16. It is commonly accepted in American society that too much sleep is ______.

　　A. unreasonable B. criminal C. harmful D. costly

　　答案：A

　　17. The research done by the Dement Commission shows that Americans ______.

　　A. don't like to naps

　　B. are terribly worried about their national debt

　　C. sleep less than is good for them

　　D. have caused many industrial and traffic accidents

　　答案：C

　　18. The purpose of this article is to ______.

　　A. warn us of the wickedness of napping

　　B. explain the danger of sleepiness

　　C. discuss the side effects of napping

　　D. convince the reader of the necessity of napping

　　答案：D

　　19. The "American sleep debt" (Line 1, Para.3.is the result of ______.

　　A. the traditional misconception the Americans have about sleep

　　B. the new sleep policy of Clinton Administration

　　C. the rapid development of American industry

　　D. the Americans' worry about the danger of sleepiness

　　答案：A

　　20. The second sentence of the last paragraph tells us that it is ______.

　　A. preferable to have a sound sleep before a night shift

　　B. good practice to eat something light before we go to bed

　　C. essential to make up for lost sleep

　　D. natural to take a nap whenever we feel the need for it

　　答案：D