Inearliesttimesmenconsideredlightning（闪电）tobeoneofthegreatmysteries（神密）ofnature．Someancientpeoplebelievedthatlightningandthunderweretheweapons(武器)ofthegods．
In earliest times men considered lightning （闪电）to be one of the great mysteries（神密） of nature． Some ancient people believed that lightning and thunder were the weapons(武器) of the gods．
In reality lightning is a flow of electricity （电流）formed high above the earth． A single flash（闪烁） of lightning 1.6 kilometers long has enough electricity to light one million light bulbs．
The American scientist and statesman Benjamin Franklin was the first to show the connection between electricity and lightning in 1752． In the same year he also built the first Lightning Rod (避雷针)． His device（发明物） protects buildings from being damaged by lightning．
Modern science has discovered that one stroke of lightning contains more than 15 million volts(伏特)． A spark（火花） between a cloud and the earth may be as long as 13 kilometers and travel at a speed of 30 million meters per second．Scientists estimate (估计) that there are about 2 000 million flashes of lightning per year． Lightning hits the Empire State Building in New York City 30 to 48 times a year． In the United States alone it kills an average of one person every day．
The safest place to be in case of an electrical storm is in a closed car． Outside one should go to low ground and not get under trees． Also one should stay out of water and away from metal fences． Inside a house people should avoid open doorways and windows and not touch wires or metal things．
With lightning it's better to be safe than sorry.
Lightning is actually ＿＿＿＿＿．
A．weapon B．electricity C．light D．mystery
People once thought that lightning came from ＿＿＿＿＿＿．
A．scientists B．ground C．lightning rod D．gods
Benjamin Franklin ＿＿＿＿＿＿．
A. made the first lightning rod B．built the Empire State Building
C. invented electricity D．prevented lightning from hitting cars
＿＿＿＿＿＿is the best place to be in during an electricity storm．
A．Swimming pool B. A high place C．Under a tree D．A car
【小题1】B
【小题1】D
【小题1】A
【小题1】D
解析:
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