In old times，man considered lightning to be one of the great mysteries（神秘事物）of n

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In old times，man considered lightning to be one of the great mysteries（神秘事物）of nature．In fact a single flash of lightning 1.6 kilometers long has enough electricity to light one million lamps．
The American scientist，Benjamin Franklin，was the first to suggest that lightning is in fact electricity formed between the earth and clouds high above．It happened in 1752．In the same year，he also built the first lightning rod（避雷针）to protect buildings from being struck by lightnings．
Modern science has discovered that lightning is very strong and powerful．A lightning between a cloud and the earth may be as long as 13 kilometers，and travels at a speed of 30 million meters per second．Scientists have the opinion that there are about 2000 million flashes of lightning per year．In the United States alone，it kills almost one person per day．
The safest place to be in during an electrical（电的）storm is a closed car．Outside，one should go close to low ground for cover and not stop under a tree．Also one should stay out of water and away from metal fences．Inside a house people should keep away from open doorways and windows and not touch wires or metal things．
小题1:From this passage we know lightning is____．

A．one of the great mysteries of nature．

B．electricity high above the earth．

C．a kind of light．

D．the sound from the clouds．

小题2:In the U．S____．

A．every person can see lightning every day．

B．at least one person is killed by lightning every day．

C．there are about 6 million flashes of lightning per year．

D．about one person per day dies from lightning．

小题3:During a lightning storm，it would be best if you____．

A．stand under a tree．

B．go outside．

C．stay in a closed car．

D．stop near windows．

小题4:A lightning rod can______．

A．prevent accidents caused by lightning

B．stop lightning

C．protect buildings from being washed away．

D．delay the coming of lightning

小题5:A lightning between a cloud and the earth may be 13 kilometers long，and travels at
a speed of ______．

A．30 kilometres per second．

B．3000 kilometres per second

C．3 kilometres per second

D．30，000 kilometres per second

答案

小题1:B
小题2:D
小题3:C
小题4:A
小题5:D

解析

1. B 本题考查闪电的定义，根据in fact electricity formed between the earth and clouds high above可知B答案正确。
2. D 细节题。由下文In the United States alone，it kills almost one person per day，几乎每天***死一个人，故选D。
3. C 同样是细节题的考查。文章The safest place to be in during an electrical（电的）storm is a closed car可知在紧闭的车里是最安全的，故选C。
4. A 本题问避雷针的作用，根据the first lightning rod（避雷针）to protect buildings from being struck by lightnings可知是用来保证不被雷击，而C保护建筑物不被冲走不对，故选A阻止被雷击事故的发生。
5. D 考查单位之间的转换。文章说30 million meters per second，即3000万米每秒，换成千米就是30000万千米，故选D。