首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The modem age is an age of electricity. People are so used to electric lights, radios, televisions, and telephones that it is ba
The modem age is an age of electricity. People are so used to electric lights, radios, televisions, and telephones that it is ba
admin
2010-06-01
87
问题
The modem age is an age of electricity. People are so used to electric lights, radios, televisions, and telephones that it is bard to imagine what life would be like without them. When there is a power failure, people grope (摸索) 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 millions 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 cells sent out tiny pulses of electricity. As the heart beats, it sends out pulses that can be measured and recorded on the surface of the body. When the pulses are recorded, they form an electrocardiogram(心电图), 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--of- ten so small that sensitive instruments are needed to record them. But in some animals, certain muscled cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cells are linked together, the effect can be astonishing.
The electric eel is an amazing living storage battery. It can send a jolt of as much as eight hundred volts of electricity through the water in which it lives. ( 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 the length of its body.
Why does the author mention electric eels?
选项
A、To warn the reader to stay away from them.
B、To compare their voltage to that used in houses.
C、To give an example of a living electrical generator.
D、To describe a new source of electrical power.
答案
C
解析
文中最后一段提到As many as four-fifths of all the cells in the electric eel’s body are specialized for generating electricity。
转载请注明原文地址:https://kaotiyun.com/show/1oN7777K
0
大学英语四级
相关试题推荐
Adifficultorabusivebosscanpoisonthebestofjobs.Butyouarenotpowerless;beforeyouevenconsiderquitting,trytheb
A、Sheasksifshecanbringafriendtotheparty.B、Sheasksifshecanbringhersistertotheparty.C、Sheasksifshecanbe
EconomyTerrorizedFromWallStreettoMainStreet,Layoffs,Losses,andLittleHopeThepopularwordinbusinessbefo
A、Theythinktheyareoverpriced.B、Theythinktheyhavebeenstolen.C、Theythinktheyareinpoorworkingcondition.D、Theyt
A、Helackstime.B、Helackswillpower.C、Helackssleep.D、Helacksmedicine.B
Todayitisperfectlynaturalforustoshakehandswhenwegreetsomeone,orsaygood-bye.Butlikesomanyotherthingswedo
A、Hewaswanderingonthestreet.B、Hewasworkinginthepark.C、Hewaswalkinghomefromwork.D、Hewasdrivinghomefromwork
Americansocietyisnotnap-friendly.Infact,there’sevena【B1】______againstadmittingweneedsleep.Nobodywantstobecaugh
Thecompanyshouldbebrokenupintotwoentities,onetodevelopoperatingsystem,______(另外一个促进)softwareapplications.
A、Theadvantagesanddisadvantagesofcomputers.B、Thefutureofthecomputer.C、Themainfeaturesofthecomputer.D、Thescient
随机试题
下列哪项既是症状也是体征()
患者,男,20岁,脑桥变粗,T1WI表现为稍低信号,T2WI为高信号,基底动脉被包绕,向前移,第四脑室底后移,该病变可能为
以下哪项会使收益下降?
商业银行授信审批一般应当遵循审贷分离、统一考虑和展期重审的原则。()
以下是张老师的教学手记节选。李明是我的学生,他父母离异。因为缺少双亲的关爱,李明比较不合群,经常迟到、旷课,常因一点小事就向同学大打出手。看到这一切,我没有因他违反纪律而训斥、挖苦他,而是用母亲般的爱去关心他、爱护他。在一个秋风萧瑟的早晨,我在教
Tryingnewthingsistheonlywaywecandiscoverhiddentalents.I【C1】________mycareerasaneditorforamagazine.Ididn’tr
已知α=是可逆矩阵A=的伴随矩阵A*的特征向量,特征值λ.求a,b,λ.
Themiddle-agedmanwasseen______outofthehouseontheafternoonofthemurder.
Anniewasbusy______herboyfriendlastnight.
WhydidSusanandMichaelinterviewchildrenagedbetween9and11?
最新回复
(
0
)