首页
登录
职称英语
The idea of a fish being able to generate electricity strong enough to light
The idea of a fish being able to generate electricity strong enough to light
游客
2024-08-07
19
管理
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, of which several kinds live in warm seas. They possess 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 fiat 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 centimetres 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 and are supplied with nerves from the spinal 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 to tire, so they are not able to produce electricity for very long.
The electric catfish of the Nile and of other African fresh waters has a different system again, by which current passes over the whole body from the tail to the head. The shock given by this arrangement is not so strong as the other two, but is none the less unpleasant. The electric catfish is a slow, lazy fish, fond of gloomy places and grows to about 1 metre long; it is eaten by the Arabs in some areas.
The power of producing electricity may serve these fish both for defence and attack. If a large enemy attacks, the shock will drive it away; but it appears that the catfish and the electric eel use their current most often against smaller fish, stunning them so that they can easily be overpowered.
For answers 51-55, mark
Y(for YES) if the statement agrees with the information given in the passage;
N (for NO) if the statement contradicts the information, given in the passage;
NG(for NOT GIVEN) if the information is not given in the passage. [br] The fish that produce electricity belong to ______.
选项
答案
different families
解析
由第一段最后一句“by fish belonging to very different families”可知答案为different families。
转载请注明原文地址:https://tihaiku.com/zcyy/3710039.html
相关试题推荐
Theideaofafishbeingabletogenerateelectricitystrongenoughtolight
Theideaofafishbeingabletogenerateelectricitystrongenoughtolight
Theideaofafishbeingabletogenerateelectricitystrongenoughtolight
Theideaofafishbeingabletogenerateelectricitystrongenoughtolight
Theideaofafishbeingabletogenerateelectricitystrongenoughtolight
Theideaofafishbeingabletogenerateelectricitystrongenoughtolight
______enoughtimeandmoney,theresearcherswouldhavebeenabletodiscovermo
Bluesisatypeofmusicofstrongrhythm,whichwasoriginallysungby______.A、
______enoughtimeandmoney,theresearcherswouldhavebeenabletodiscovermo
Whatmeasureismentionedinthenews?[originaltext]Heavyrainsandstrongwind
随机试题
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatisthe
It’shotnowinAfghanistan,where35%ofthepopulationisunder-fed.Buts
男,78岁。发生老视,其原因主要是()。A.角膜曲率改变 B.角膜透明度改变
请阅读Passage2,完成第小题。 Passage2 Thatexp
下列各项中,能引起权益法核算的长期股权投资账面价值发生变动的有( )。A.被投
2020年全国农民工总量28560万人,下降1.8%,其中,外出农民工16959
某社区开展了为期一年的预防艾滋病健康教育活动。活动结束后,评估人员从不同层面对活
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
在tn-c系统中,pen线()接人开关设备。 a.一般不得;B严禁;c
关于招投标管理机构及其职责,以下说法错误的是()。A.建设部负责全国工程建设施
最新回复
(
0
)