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
2023-08-17
38
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/2935022.html
相关试题推荐
[originaltext]W:Thankyou,thankyouandwelcometoeveryone’sfavoritegames
[originaltext]W:Hmm,hi.M:Hi,Iamgoingdoortodoortonighttotellpeople
[originaltext]W:Hmm,hi.M:Hi,Iamgoingdoortodoortonighttotellpeople
[originaltext]M:IfIeverseethatguyagain,I’mdefinitelygoingtotellhim
[originaltext]M:IfIeverseethatguyagain,I’mdefinitelygoingtotellhim
[originaltext]M:IfIeverseethatguyagain,I’mdefinitelygoingtotellhim
[originaltext]M:IfIeverseethatguyagain,I’mdefinitelygoingtotellhim
[originaltext]WhenMidoriwastwoyearsold,sheoftenclimbedontothepia
[originaltext]WhenMidoriwastwoyearsold,sheoftenclimbedontothepia
[originaltext]WhenMidoriwastwoyearsold,sheoftenclimbedontothepia
随机试题
Thedefendinglawyerquicklyspottedthe______intheallegationsmadebythep
PassageThree[br]Whatisthispassagemainlyabout?Thepowerofartandcultur
测定土工织物厚度时,压力等级可选择()。A.2kPa B.20kPa C.
5个月健康男婴,出生体重3kg,因母亲有慢性病,给予人工喂养,喂以牛奶。下列有关
2008年国际金融危机暴露出银行流动性风险管理存在的不足,包括()。A.压力测
缓释制剂的释药机理是A.减小药物的扩散速度和减小药物的溶出速率,用药后能在较长时
以下哪种方法不适合规划方案选择?( )A.线性规划法 B.费用效益分析法
大量出血的同时,气随血的突然流失而脱散是指A.气不摄血 B.气血两虚 C.气
男,30岁。咽痛、咳嗽、发热,2周后发现尿色红,眼睑水肿,尿量1000ml/24
银行期末按被投资单位实现的净利润计算应分享的金额。其会计分录为( )。A.借:损
最新回复
(
0
)