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
专升本
The idea of a fish being able to generate electricity strong enough to light lamp bulbs--or even to run a small electric motor--
The idea of a fish being able to generate electricity strong enough to light lamp bulbs--or even to run a small electric motor--
admin
2011-04-26
36
问题
The idea of a fish being able to generate electricity strong enough to light lamp bulbs--or even to run a small electric motor--is almost unbelievable, but several kinds of fish are able to do this. Even more strangely, this curious power has been acquired in different ways by fish belonging to very different families.
Perhaps the best known are the electric rays, or torpedoes (电鱼), of which several kinds live in warm seas. They posses on each side of the head, behind the eyes, a large organ consisting of a number of hexagon- al shaped cells rather like a honeycomb. The cells are filled with a jelly-like substance, and contain a series of flat electric plates. One side, the negative side, of each plate, is supplied with very fine nerves, connected with a main nerve coming from a special part of the brain. Current passes from the upper, positive side of the organ downwards to the negative, lower side. Generally it is necessary to touch the fish in two places, completing the circuit, in order to receive a shock.
The strength of this shock depends on the size of the fish, but newly born ones only about 5 centimeters across can be made to light the bulb of a pocket flashlight for a few moments, while a fully grown torpedo gives a shock capable of knocking a man down, and, if suitable wires are connected, will operate a small electric motor for several minutes.
Another famous example is the electric eel. This fish gives an even more powerful shock. The system is different from that of the torpedo in that the electric plates run longitudinally (纵向) and are supplied with nerves from the spinal(脊骨)cord. Consequently, the current passes along the fish from head to tail. The electric organs of these fish are really altered muscles and like all muscles are apt (likely) to tire, so they are not able to produce electricity for very long.
The power of producing electricity may serve these fish both for defence and attack.
Usually you will not get a shock by touching the electric ray in one place only because ______. ( )
选项
A、the current in one place is not strong enough to give a shock
B、the fish’s electric cells are filled with jelly-like substance
C、to complete the circuit, you have to touch the fish in two places
D、a torpedo: s electric cells contain more than one electric plates
答案
C
解析
转载请注明原文地址:https://jikaoti.com/ti/GS4GFFFM
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Thepowerofwords,then,liesintheirassociations--thethingstheybringupbeforeourminds.
WhydidStanleyWilliamswriteanti-gangbooks?WhatdoesWilliamsreallywanttotellyoungpeople?
Accordingtothepassage,beesarefittedforcommunallifebyvirtueoftheir______.Thehoneybee’sstingisparticularlyeff
Let’s______whentheshipwillarrive.
I’mnotsurprisedyoufailedtheexam.You______haveworkedharder.
Japanesecarsalesmenusuallydonotwaitatshowroomsforcustomerstodropby;instead,______.Japanesecarsalesmendothei
Hesuggestedthatthey______useatrickinsteadoffighting.
Thisstoryis【21】afarmhandandalandlord.Thefarmhandworkedhardalldaylong.【22】hegotvery【23】moneyandneverhadmuchto
TheYellowRiveristhesecond______riverinChina.
随机试题
小柴胡汤中,君药是小柴胡汤中,臣药是
患儿,男,1岁。诊断为室间隔缺损8个月。3天前出现发热,咳嗽,近1天来,咳嗽、呼吸急促,三凹症明显,尿少,急诊入院。查体:T38℃、P160次/分,R55次/分,肝肋下5cm。诊断室间隔缺损合并心力衰竭。服用强心苷时,可观察到循环系统的中毒反应有
院内感染所致肺炎中,主要病原体是()。
后张法预应力筋张拉时,要求混凝土弹性模量应不低于28d弹性模量的()。
证券经纪商禁止发生下列()行为。
据企业破产法律制度的规定,下列债务中,债权人应在人民法院确定的期限内进行债权申报的有()。
现代教学设计有哪些基本特征?
你有工作能力但得不到领导的认可怎么办?
春山暖日和风∶阑干楼阁帘栊
Tight-lippedeldersusedtosay,"It’snotwhatyouwantinthisworld,butwhatyouget."Psychologyteachesthatyoudogetw
最新回复
(
0
)