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
2024-02-16
3
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(电鳐), 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 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 centime-tres 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. [br] The reason why the electric eel is able to give more powerful shock is that______.
选项
A、the working system of the electric plates in the eel is the most effective
B、the working system of the electric plates in the eel is far inferior to those in the torpedo
C、compared with those in the torpedo, the working system of electric plates in the eel is more direct and efficient
D、compared with other electric fish, the eel possesses much more electric plates
答案
C
解析
在第四段中,作者详细地说明了电鳗的发电系统,电鳗的发电组织是纵向的,由脊骨的神经供电,因而电流从头至尾流动。而电鳐的发电器官是蜂窝状且分布于头部两侧,可以看山电鳗由于其脊骨神经供电,电流可直接由头传至尾,较顺畅,可推断出电鳗的发电系统较之电鳐更直接也更有效一些,所以应选C项。
转载请注明原文地址:https://tihaiku.com/zcyy/3454675.html
相关试题推荐
[originaltext]EnglandbecameastrongholdoftheProtestantversionofChri
LanceArmstrongisthirty-threeyearsoldandisoneofthebestathletesin
LanceArmstrongisthirty-threeyearsoldandisoneofthebestathletesin
LanceArmstrongisthirty-threeyearsoldandisoneofthebestathletesin
LanceArmstrongisthirty-threeyearsoldandisoneofthebestathletesin
LanceArmstrongisthirty-threeyearsoldandisoneofthebestathletesin
LanceArmstrongisthirty-threeyearsoldandisoneofthebestathletesin
He______(本来可以选择另一种职业),butatthetime,hedidn’thaveenoughmoney.mighthave
Strongemotionsareusually【B1】______nonverbally:Bygestures,bodyposture,
Strongemotionsareusually【B1】______nonverbally:Bygestures,bodyposture,
随机试题
Keepingafullsocialcalendarmayhelpprotectyoufromdementia(痴呆症),res
[originaltext]W:Hello.CanItakeyourorder?M:Yes.I’dlikealargepeppero
老年患者,突发剧烈胸痛,临床诊断为急性前壁心肌梗死,入院后4h心电图监测发现频繁
水泵(立式轴流泵〉或水泵进水管〔卧式离心泵、混流泵〉直接吸水的水工建筑物,一般
女,14岁,平时以罐头食品为主食,最近牙龈反复出血,皮下可见瘀斑应补充哪种食品A
2009年4月,某审计组对甲公司2008年度财务收支情况进行审计。有关销售与收款
如图所示,△ABC是底角为30°的等腰三角形,其内的矩形DEFG是由两个边长为1
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
心悸怔忡,失眠多梦,眩晕耳鸣,目涩肢麻,爪甲不荣,舌淡脉细,属A.心血虚证 B
意味着巴塞尔新资本协议和巴塞尔协议Ⅲ在我国全面实施的是()。A.《中华人民
最新回复
(
0
)