Yet, people began to understand how electricity works only a little more than two centuries ago. Nature has apparently been experimenting in this field for million of years. Scientists are discovering more and more that the living world may hold many interesting secrets of electricity that could benefit humanity.
All living cell send out tiny pulses of electricity. As the heart beats, it sends out pulses of record; they form an electrocardiogram, which a doctor can study to determine how well the heart is working. The brain, too, sends out brain waves of electricity, which can be recorded in an electroencephalogram. The electric currents generated by most living cells are extremely small often so small that sensitive instruments are needed to record them. But in some animals, certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cell are linked together, the effects can be astonishing.
The electric eel is an amazing storage battery. It can seed a jolt of as much as eight hundred volts of electricity through the water in which it live. As many as four-fifths of all the cells in the electric eels body are specialized for generating electricity, and the strength of the shock it can deliver corresponds roughly to length of its body.
上一篇: 暑期备考六级优秀范文每日一背(21)
下一篇: 暑期备考六级优秀范文每日一背(1)
2017届高考英语一轮复习指导课件:必修2 unit 3(新人教版)
2017届高考英语一轮全册复习课时作业:选修8.2《Cloning》(新人教版含解析)
2017届高考英语一轮全册复习课时作业:选修8.1《A land of diversity》(新人教版含解析)
2017届高考英语一轮全册复习课时作业:选修7.3《Under the sea》(新人教版含解析)
国际英语资讯:Ten killed in subway explosion in Russias St. Petersburg
体坛英语资讯:Xinjiang take 2-0 lead at home in 2017 CBA finals
2017届高考英语一轮全册复习课时作业:选修8.3《Inventors and inventions》(新人教版含解析)
2017届高考英语一轮复习指导课件:必修1 unit 5(新人教版)
2017届高考英语一轮复习指导课件:必修1 unit 3(新人教版)
研究:跑马拉松伤肾
国内英语资讯:Commentary: Xiongan New Area to catalyze Chinas inclusive growth
国际英语资讯:Spotlight: S. Korean civic groups moving to oppose THAAD deployment
你认为最好的职业是什么?
体坛英语资讯:Shandong Luneng top CSL standings with three straight wins
2017届高考英语一轮复习指导课件:必修2 unit 4(新人教版)
体坛英语资讯:Feature: American snow flying in Chinese skies as Beijing 2022 Winter Games take shape
2017届高考英语一轮全册复习课时作业:选修8.5《Meeting your ancestors》(新人教版含解析)
2017届高考英语一轮全册复习课时作业:选修8.4《Pygmalion》(新人教版含解析)
2017届高考英语一轮全册复习课时作业:选修7.2《Robots》(新人教版含解析)
2017届高考英语一轮全册复习课时作业:选修7.4《Sharing》(新人教版含解析)
国内英语资讯:Full Text of Chinese presidents signed article in Finnish newspaper
体坛英语资讯:Ajax beat Feyenoord 2-1 to close in on championship rivals
2017届高考英语一轮复习指导课件:必修2 unit 1(新人教版)
2017版《三年高考两年模拟》高考英语汇编专题:专题6 动词的时态和语态(含解析)
2017届高考英语一轮复习指导课件:必修1 unit 2(新人教版)
国内英语资讯:Senior Chinese, U.S. officials agree Xi-Trump meeting significant for bilateral ties
国际英语资讯:Ukrainian, French, German leaders urge truce consolidation in eastern Ukraine
2017届高考英语一轮复习指导课件:必修1 unit 4(新人教版)
2017版《三年高考两年模拟》高考英语汇编专题:专题7 非谓语动词(含解析)
2017版《三年高考两年模拟》高考英语汇编专题:专题5 动词和动词短语(含解析)