64、(1分)

   In earliest times, men considered lightning to be one of the great mysteries (神秘的事物) of nature. Some ancient peoples believed that lightning and thunder were the weapons (武器) of the gods.

   In reality, lightning is a flow of electricity formed high above the earth. A single flash of lightning 1.6 kilometres long has enough electricity to light one million light bulbs (灯泡).

   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). This device (装置物) protects buildings from being damaged by lightning.

   Modern science has discovered that one stroke (闪击) of lightning has a voltage (电压) of more than 15 million volts (伏特). A flash of lightning 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 judge 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 (平均数) 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 tress. 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 is better to be safe than sorry?

 0  252236  252244  252250  252254  252260  252262  252266  252272  252274  252280  252286  252290  252292  252296  252302  252304  252310  252314  252316  252320  252322  252326  252328  252330  252331  252332  252334  252335  252336  252338  252340  252344  252346  252350  252352  252356  252362  252364  252370  252374  252376  252380  252386  252392  252394  252400  252404  252406  252412  252416  252422  252430  447348 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网