04 Electricity
The modern age is an age of electricity. People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them. When there is a power failure, people grope about in flickering candlelight, cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators.
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, cert 04 Electricity
The modern age is an age of electricity. People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them. When there is a power failure, people grope about in flickering candlelight, cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators.
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.
ain 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.
跳槽能给你带来什么好处?
怎样处理职场上的暴力行为(上)
如何知道自己是否该换工作?
在众人前表达自己的观点
帮你少加班 早下班的方法
职场面试中的五个"失策"
你对自己的工作消沉倦怠了吗?(1)
简历的首页应该怎样写?
提高工作效率 避免浪费时间
让员工"拥有"工作的成功老板(2)
给应届毕业生的求职建议
怎样跟别人说"不"
表达不同意见而不是"好斗"
如何在逆境中取胜?
成就感可以帮助缓解工作疲劳
办公室为人处事的原则
怎样提高工作满意度(2)
给准备参加招聘会的人支招
走进新岗位的自我介绍
怎样提高工作满意度(1)
寻找职业生涯的真正成功
各国外企对英文简历的不同要求
让自己专心工作的窍门
培训在工作中的重要性
是什么让你对工作不满
学会委派别人工作
你的工作还顺心吗?(上)
怎样缓解工作上的压力
你是否在工作中缺乏主张?
网上找工作的方法(2)
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |