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
2023-10-13
37
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 catfish’s electric current passes from the ______.
选项
答案
tail to the head
解析
由第五段第一句“current passes over the whole body from the tail to the head”可知答案为tail to the head。
转载请注明原文地址:https://tihaiku.com/zcyy/3095424.html
相关试题推荐
Iamfascinatedbythemen,fewenoughinallconscience,whotakelifeinthei
Researchshowsthatifwedon’t__________enoughvitaminD,wewilldevelophea
TheOlympicmottoismadeupofthreewords:FASTER—HIGHER—STRONGER.Themottoc
DevelopingEnvironmentalManagementStrategiesStrongandsus
DevelopingEnvironmentalManagementStrategiesStrongandsus
DevelopingEnvironmentalManagementStrategiesStrongandsus
Excessivesugarhasastrongmal-effectonthefunctioningofactiveo【66】su
Excessivesugarhasastrongmal-effectonthefunctioningofactiveo【66】su
Excessivesugarhasastrongmal-effectonthefunctioningofactiveo【66】su
Excessivesugarhasastrongmal-effectonthefunctioningofactiveo【66】su
随机试题
Myfriend’smotherremarkedonthe"plush"seatswehadbeengiven.Ididnotkno
PASSAGEFIVE[br]Wheredotradersmostlytradederivativesaccordingtothepas
在一限定空间内,可燃物的表面局部卷入燃烧的瞬变状态称为轰燃。()
制订食物与营养现场工作计划的3个妥善原则是( )。A.妥善地编制预算、利用时间
《商业银行合规风险管理指引》规定,商业银行应建立与其经营范围、组织结构和业务规模
A.西红花B.西洋参C.鹿茸D.麝香E.牛黄可与花椒共同贮藏以防生虫的是
小月今年刚刚大学毕业便在一家不错的企业谋到了自己喜欢的岗位,本来兴冲冲的她已经工
培训效果的问卷调查评估不适用于()。A.了解学员偏爱的学习方法 B.让学员清
股票买卖印花税最后由()统一向征税机关缴纳。A:中国结算公司B:证券交易所C
女,22岁。每逢路过商店时就会有被售货员怀疑偷窃的想法,无法自控,十分痛苦。遂到
最新回复
(
0
)