Although April did not bring us the rains we all hoped for, and although the Central Valley doesn’t generally experience the atmospheric sound and lightning that can accompany those rains, it’s still important for parents to be able to answer the youthful questions about thunder and lightning. The reason these two wonders of nature are so difficult for many adults to explain to children is that they are not very well understood by adults themselves. For example, did you know that the lightning we see flashing down to the earth from a cloud is actually flashing up to a cloud from the earth? Our eyes trick us into thinking we see a downward motion when it’s actually the other way around. But then, if we believed only what we think we see, we’d still insist that the sun rises in the morning and sets at night. Most lightning flashes take place inside a cloud, and only a relative few can be seen jumping between two cloud or between earth and a cloud. But, with about 2, 000 thunderstorms taking place above the earth every minute of the day and night, there’s enough activity to produce about 100 lightning strikes on earth every second. Parents can use thunder and lightning to help their children learn more about the world around them. When children understand that the light of the lightning flashing reaches their eyes almost at the same moment, but the sound of the thunder takes about 5 seconds to travel just one mile, they can begin to time the interval between the flash and the crash to learn how close they were to the actual spark.

Many difficulties______ as a result of the change over to a new type of fuel. risen arisen arose raised

She thought it was______not to know some of the basic facts of her country. shameful ashamed a shame ashameful

How many more decades will have to pass ______ scientists succeed in providing a cure for cancer? when since before until

Nuclear science should be developed to benefit the people______harm them. more than better than other than rather than

There are some______ flowers on the desk. artificial false unreal untrue

Some discussion has______about who should be put in charge of this project. risen lifted raised arisen

I don’t think I know the girl with long hair although she______me of someone I know. remembers recalls suggests reminds

Although the examination he had passed was unimportant, his success______ him in his later study. persuaded promised urged encouraged

Although he had looked through all the reference material on the subject, he still found it hard to understand this point and her explanation only______ to his confusion. extended amounted added turned

American society is not nap(午睡)friendly. In fact, says David Dinges, a sleep specialist at the University of Pennsylvania 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 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 percent of American adults nap when given the opportunity. We seem to have “a midafternoon quiet phase“ also called “a secondary sleep gate. “ Sleeping 15 minutes to two hours in the early afternoon can reduce stress and make us refreshed. Clearly, we were born to nap. We Superstars 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 on boats; on floors and beds; and in libraries, offices and museums.

Although April did not bring us the rains we all hoped for, and although the Central Valley doesn’t generally experience the atmospheric sound and lightning that can accompany those rains, it’s still important for parents to be able to answer the youthful questions about thunder and lightning. The reason these two wonders of nature are so difficult for many adults to explain to children is that they are not very well understood by adults themselves. For example, did you know that the lightning we see flashing down to the earth from a cloud is actually flashing up to a cloud from the earth? Our eyes trick us into thinking we see a downward motion when it’s actually the other way around. But then, if we believed only what we think we see, we’d still insist that the sun rises in the morning and sets at night. Most lightning flashes take place inside a cloud, and only a relative few can be seen jumping between two cloud or between earth and a cloud. But, with about 2, 000 thunderstorms taking place above the earth every minute of the day and night, there’s enough activity to produce about 100 lightning strikes on earth every second. Parents can use thunder and lightning to help their children learn more about the world around them. When children understand that the light of the lightning flashing reaches their eyes almost at the same moment, but the sound of the thunder takes about 5 seconds to travel just one mile, they can begin to time the interval between the flash and the crash to learn how close they were to the actual spark.

你可以从你的兄弟那儿借些钱。

As a result of careless washing, the jacket______to a child’s size. compressed shrank dropped decreased

Some old people don’t like pop songs because they can’t______ so much noise. resist sustain tolerate undergo

In developing countries, people are______ into overcrowded cities in great numbers. breaking filling pouring hurrying

Your hair wants______. You’d better have it done tomorrow. cut to cut cutting being cut

______, the book has many mistakes. Having not been written carefully Not writing carefully Having written not carefully Not having been written carefully

I went to my adviser to ask him what courses______. should I take must I take to take I were to take

Ted agreed to______the strike if the company would satisfy the demand of the workers. call out call to call off call on

I need______more volunteers to help move the piano. none any few some

We believe that lightning is a downward notion because______.

The word “activity“(Para. 3, Line 4)is most closely related to the word(s)

According to the author, in the area of the Central Valley, ______.

What is TRUE about lightning according to the passage?

It can be concluded from the passage that______.