Although April did not bring us the rains we all hoped for, and although the Central Valley doesn’t generally experience the sound and lightning that can go with 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 and we see, we’d still insist that the sun rises in the monring and sets at night.

Most lightning flashes take place inside a cloud, and only a relative few can be seen jumping between two clouds 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(间隔) between the flash and the crash to learn how close they were to the actual spark(闪光).

46. Accodring to the author, in the area of the Central Valley____.

   A. rains usually come without thunder and lightning.

   B. it is usually dry in April

   C. children pay no attention to the two natural wonders.

   D. parents are not interested in thunder an lightning.

47. We believe that lightning is a downward motion because_______.

   A. we were taught so by our parents from our childhood.

   B. we are taken in by our sense of vision.

   C. it is a common natural sight.

   D. it is a truth proved by science.

48. What is TRUE about lightning according to the passage?

   A. Only a small number of lightning flashes occur on earth.

   B. Lightning flashes usually jump from one cloud to another.

   C. Lightning travels 5 times faster than thunder.

   D. There are far more lightning strikes occurring on earth than we can imagine.

49. The underlined word “activity” is most closely related to the word(s) _____.

   A. cloud           B. lightning strikes         C. lightning flashes        D. thunderstorms

50. It can be concluded from the passage that _______.

   A. we should not believe what we see or hear.

   B. things moving downward are more noticeable.

   C. people sometimes may have wrong ideas about ordinary phenomena.

   D. adults are not as good as children in observing certain natural phenomena.