首页
登录
职称英语
[originaltext] To us, the environment in which fish dwell often seems cold,
[originaltext] To us, the environment in which fish dwell often seems cold,
游客
2024-04-12
20
管理
问题
To us, the environment in which fish dwell often seems cold, dark and mysterious. But there are advantages to living in water.(22)And they’ve played an important role in making fish what they are. One is that water isn’t subject to sudden temperature changes. Therefore it makes an excellent habitat for a cold blooded animal. Another advantage is the water’s ability to easily support body weight. Protoplasm has approximately the same density as water. So a fish in water is almost weightless. This weightlessness in turn means two things:
1)A fish can get along with a light weight and a simple bone structure. And
2)Limitations to a fish’s size are practically removed.(20)Yet there is one basic difficulty to living in water—the fact that it is incompressible. For a fish to move through water, it must actually shove it aside.(21)Most can do this by wiggling back and forth in snake-like motion. The fish pushes water aside by the forward motion of its head and with a curve of its body and its flexible tail. Next the water flows back along the fish’s narrowing sides, closing in at the tail and helping the fish propel itself forward. The fact that water is incompressible has literally shaped the development of fish. A flat and angular shape can be moved through water only with difficulty. And for this reason, fish have a basic shape that is beautifully adapted to deal with this peculiarity.
20. What does the speaker mention as a problem that water presents to fish?
21. The speaker compares a fish’s movement with that of what creature?
22. What is the talk mainly about?
选项
A、A comparison of fish to warm-blooded animals.
B、The difference between saltwater and freshwater environments.
C、The importance of fish to human beings.
D、How water has affected the development of fish.
答案
D
解析
由“And they’ve played an im—portant role in making fish what they are.”可知本讲座内容为水是如何影响鱼的发展的。所以答案选D)。
转载请注明原文地址:https://tihaiku.com/zcyy/3551282.html
相关试题推荐
[originaltext]We’vejustseentwocontemporarylargebirdsthatcannotfly—
[originaltext](20)In1871thefirstpassengerelevatorswereusedinoffic
[originaltext](16)Ineedtomakesureyouunderstandhowtogethousingfo
[originaltext](16)Ineedtomakesureyouunderstandhowtogethousingfo
[originaltext](12)Firstaidmaybedefinedastheimmediateandtemporary
[originaltext](12)Firstaidmaybedefinedastheimmediateandtemporary
[originaltext]IfyouareinanymajorcityinAmerica,thechancesarehigh
[originaltext]IfyouareinanymajorcityinAmerica,thechancesarehigh
[originaltext]IfyouareinanymajorcityinAmerica,thechancesarehigh
[originaltext]W:Hi,Peter,Iknowyouareagreatfanofsports,right?M:Ye
随机试题
Thisisofferedasatextbookillustrationoftheprinciplethatvotersare
神经阻滞疗法是通过阻断痛觉的神经传导通路、阻断疼痛的恶性循环、抗炎等达到镇痛目的
矿坑水文地质调查包含多项内容,下列选项中不属于出水点调查的主要内容的是()。?A
下列房地产经纪服务合同条款中,不属于实体条款的是( )。A.标的条款 B.价
Thechangeinthatvillagewasmiraculou
下列说法中错误的是( )A.研究的信度高低说明研究和研究结果是否可重复,是否具
外国人在中华人民共和国领域外对中国公民犯罪,适用中国刑法的必要条件有( )。A
下列以职位为导向的基本薪酬制度设计方法中,()是需要确定各类职位共同的“付
针对滲透系数较大土层,适宜采用的降水技术是()降水。A.真空井点 B.轻型井
磺酰脲类药物药理作用为( )。A.可使电压依赖性钾通道开放 B.可促进胰岛素
最新回复
(
0
)