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
74
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 whale.
B、A human.
C、A snake.
D、A snail.
答案
C
解析
由“Most can do this by wigglingback and forth in snake—like motion.”可知鱼前后摆动像蛇。所以答案为C)。
转载请注明原文地址:https://tihaiku.com/zcyy/2935021.html
相关试题推荐
[originaltext](23)Inthefewminutesthatremainoftoday’sclass,(24)I’d
[originaltext](23)Inthefewminutesthatremainoftoday’sclass,(24)I’d
[originaltext]Tous,theenvironmentinwhichfishdwelloftenseemscold,
[originaltext]Tous,theenvironmentinwhichfishdwelloftenseemscold,
[originaltext]Today’slecturewe’llcenterontheprehistoricpeopleofNev
[originaltext]Thestatisticsareprettyscary:(12)Eachyear2.8millionco
[originaltext]Thestatisticsareprettyscary:(12)Eachyear2.8millionco
[originaltext]Thestatisticsareprettyscary:(12)Eachyear2.8millionco
[originaltext]JohnSmithson,oneoftheexecutiveproducers,talkingabout
[originaltext]M:Youcanhavebeef,chicken,liver,mutton.Now,peoplemightn
随机试题
Thisisanillnessthatcanresultintotalblindness______leftuntreated.A、afte
Thecommunicationsexplosionisonthescaleoftherail,automobileortele
[originaltext]M:Hi,Linda!Howhaveyoubeenrecently?W:Iprobablyshouldn’t
拔除颈部术后负压引流管的指征是:()A.负压引流液少于30ml B.负压
抗流感病毒药奥司他韦属于A.血凝素抑制剂 B.RNA聚合酶抑制剂 C.神经氨
可与吡啶和硫酸铜溶液作用并显色的镇静催眠和抗癫癎药物含有A.酰脲结构 B.酯结
一类变电站年度检修计划省公司运检部于()前报送国网运检部备案。(A)9月30
毛石基础采用的毛石形状不规则时,其高度应不小于()crn。 A.10B.
神经衰弱的常见生理症状包括()多选A.长期睡眠少且感到痛苦 B.长期睡眠
某国有企业因有违反税收征收管理法的行为,被税务机关处以8000元的罚款。假定该企
最新回复
(
0
)