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
2011-06-28
56
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 be- longing 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 hexagonal 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 arc 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 or gans 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.
It can be seen from the passage that ______.
选项
A、the capacity to generate electricity is the distinctive characteristic of the fish
B、the current travels in an upward direction from the positive side to negative side in torpedo’s electric cells
C、some fish can produce enough electricity to drive a number of electric motors
D、the torpedo’ s electric cells have a shape with six sides
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/ZJlC777K
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
Takethisbaggageand______youcanfindenoughroom.
"AMOMENT’SINATTENTIONCAUSESACCIDENTS"(Line2,Para.1)isaself-defeatingwarningbecause______.Whichofthefollowing
Somepeoplearguethatthepressureoninternationalsportsmenandsportswomenkillstheessenceofsport--thepursuitofperson
______,leavesfromcertaintreessuchasthemapleturnintobrightcolours.
Shewasupsetbecauseofherwatch,______shehadbeengivenasa21stbirthdaygift,waslost.
I’mafraidIcan’tseeyouthisafternoon,becauseI______tenniswithFrank.
LincolnisregardedasagreatPresidentpartlybecauseWhatdoestheword"assassinate"inthelastsentencemean?
Skillsaretheactivitiesthatapersondoeswell.Whatthingsareyougoodatdoing?Everyonehasmanyskills.Sometimesitis
(Nothavinggotenoughhands),wehadgreatdifficultyincarryingoutthetask.
随机试题
关于信用证支付方式的基本特点,下列说法正确的是()
甲氨蝶呤抑制嘌呤的合成,因为它抑制
1932年,首先提出心电图运动试验可作为冠心病辅助诊断方法的学者是
镇肝熄风汤的病机不涉及
什么是程序单元?
在外界刺激持续作用下感受性发生变化的现象叫()。
某教师在上课过程中发现一个学生分心,便在讲课的同时用目光凝视这个学生,引起了他的注意,促使其重新专心听讲。这位教师运用的是()。
2013年度中国出国留学人员总数为41.39万人,留学回国人员总数为35.35万人,分别比上年增长3.58%和29.53%。出国留学人员中国家公派1.63万人,单位公派1.33万人,自费留学38.43万人。回国人员中国家公派1.19万人,单位公派1.01万
A、 B、 C、 D、 A
下列叙述中正确的是
最新回复
(
0
)