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 apower 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. ( An electric house current is only one hundred twenty volts.) As many as four-fifths of all the cells in the electric eel's 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:I don't like weekend
下一篇:童年
范文推荐
- 高中主题班会设计方案|高中主题班会明确目标,规划人生
- 万圣节的传统游戏
- 高三入团志愿书400字范文模板
- 工训学生自我总结|财务工总自我总结范文
- 【对校领导班子的意见和建议】2016年校领导班子民主生活会发言稿
- 会计自我评价简历
- 2019年煤矿技师个人工作总结
- 2021公司业务员个人工作计划
- [2017年电影]全市2017年产业脱贫工作总结
- 闺蜜结婚祝福语创意幽默
- 社区工作证明范本【三篇】
- [旺饺1号自助水饺加盟]王三米自助水饺加盟
- 2014志愿者服务活动总结
- 【销售人员个人总结】精选销售人员个人年度总结
- 最新的国庆节祝福语100句
- 2021集团公司纪委年度纪检工作报告
- 我的理想演讲稿范文100字
- 父亲节的祝福语20字
- 【80后小飞机】80后小夫妻恩爱QQ签名
- 公务员个人总结公务员个人述职报告|公务员个人总结 公务员个人述职报告(三篇)