首页
登录
职称英语
[originaltext] Millions of years ago, whales lived on land and walked on fou
[originaltext] Millions of years ago, whales lived on land and walked on fou
游客
2023-08-29
79
管理
问题
Millions of years ago, whales lived on land and walked on four legs. Today, whales still have small bones that are the remains of their hind legs, but these bones can only be seen on the inside of the whale. No one knows why whales left the land to live in the water.
However, scientists can imagine that when the whales changed their environment, their bodies underwent a change — taking on a more fish-like appearance. This new form offered less resistance to the water, enabling the whales to swim faster.
Despite their fish-like form, whales are not fish. A whale will drown, just as a man will, if it stays under water too long. When a whale is under water, it closes its nostrils tightly and holds its breath. The air in its lungs becomes very hot and full of water vapor. When the whale rises to the surface and exhales, its hot breath produces a column of water vapor that rises high in the air. A man produces the same effect when he exhales warm air on a cold morning.
Whales are classified as mammals because they bear their young, rather than laying eggs, and because the mother whales give the babies milk. Like other mammals, whales have warm blood. Their blood stays at the same temperature, even when they move from hot to cold water. They keep warm in cold water because they have a thick layer of fat just under their skins. This fat is called blubber, and it is thicker on whales that spend their lives in cold water. Almost all land mammals, except man, have hair on their bodies to keep them warm, but whales, which have very few hairs, are kept warm by their fat.
Questions:
33. How does a whale keep itself warm?
34. What do we learn about the blood temperature of a whale?
35. In what way do whales distinguish themselves from other land mammals?
选项
A、By its thick layer of fat under its skin.
B、By moving frequently in the water.
C、By adjusting its blood temperature.
D、By taking in hot air.
答案
A
解析
细节题。根据文中提到的They keep warm in cold water because they have a thick layer of fat justunder their skins.(因为它们皮下有一层厚厚的脂肪,所以在冷水中可以用来保暖。)可知,鲸靠皮下脂肪取暖,答案是A。
转载请注明原文地址:https://tihaiku.com/zcyy/2967799.html
相关试题推荐
[originaltext]Iamgladthatallthemembersofourzoologyclasscouldcom
[originaltext]M:Goodmorning,class.W:Goodmorning,sir.M:Todaywe’lldisc
[originaltext]M:Goodmorning,class.W:Goodmorning,sir.M:Todaywe’lldisc
[originaltext]W:WereyouabletobookseatsforthiscomingTuesday?Theurgen
[originaltext]W:WereyouabletobookseatsforthiscomingTuesday?Theurgen
[originaltext]W:WereyouabletobookseatsforthiscomingTuesday?Theurgen
[originaltext]Asyoupreparetobecomeelementaryschoolteachers,you’llb
[originaltext]BurningfallenleavesusedtobestandardpracticeacrossNo
[originaltext]BurningfallenleavesusedtobestandardpracticeacrossNo
[originaltext]W:Allright,thatcomesto$20.75.Doyouhaveoneofourstore
随机试题
[img]2018m9s/ct_etoefz_etoeflistz_201808_0060[/img][br]Whatisthemaintopic
严重创仿病人手术麻醉期间循环管理应注意下列哪几项A.维持良好血压 B.尿量
一名男性患儿,1岁,因误吸花生米后呛咳3天入院,做胸片发现右肺肺不张,听诊右肺呼
根据《房屋建筑与装饰工程量计算规范》(GB50854-2013),关于砖砌体工程
各类非银行金融机构可以通过( )实现套期保值、资产管理、增值等目的。A.回购协
患者,女,43岁。有风湿性心脏瓣膜病史。患者于户外运动时,突然出现右侧肢体无力,
重要电力客户和有特殊供电需求及临时重要电力客户应配置外部应急电源接入装置。
论述社会主义法治理念
深圳证券交易所配股认购于()开始,认购期为()个工作日。 A.R;5
女性,30岁,因食欲不振、尿少、腹胀2个月住院。19岁检查时曾发现肝大。查体:消
最新回复
(
0
)