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
2024-05-04
16
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、Grows colder as the blubber accumulates.
B、Remains the same.
C、Varies according to the water temperature.
D、Grows warmer as the whale grows older.
答案
B
解析
细节题。文中提到的Their blood stays at the same temperature,even when they move from hot to coldwater.(即使是从暖水游到冷水,它们的体温也保持不变。)表明,鲸的体温是恒定不变的,答案是B。
转载请注明原文地址:https://tihaiku.com/zcyy/3584064.html
相关试题推荐
[originaltext]WhenMidoriwastwoyearsold,sheoftenclimbedontothepi
[originaltext]WhenMidoriwastwoyearsold,sheoftenclimbedontothepi
[originaltext]Doyouknowhowtoadvertiseforahank?Ifyouaskpeopleab
[originaltext]WhoisthemostimportantpersonintheUnitedStates?Someo
[originaltext]WhoisthemostimportantpersonintheUnitedStates?Someo
[originaltext]W:Wouldyoumindtellinguswhatyouwouldliketobedoingfive
[originaltext]W:Wouldyoumindtellinguswhatyouwouldliketobedoingfive
[originaltext]W:Wouldyoumindtellinguswhatyouwouldliketobedoingfive
[originaltext]M:Hi,Janet.Youaresoluckytobedonewithyourfinalexamsa
[originaltext]W:I’dliketobookoneeconomy-classtickettoParisforthisSa
随机试题
______byRalphWaldoEmersoniscalled"America’sDeclarationofIntellectualIn
BasicsaboutSpringBreakSafety1.TravelsafetyValiddriving【T1】______Aw
Robotsareusefulinexploringspacebecausetheycanworkintheconditions
自然人的民事权利能力的特征包括( )。A.与民事主体人身不可分离 B.普遍性
《公路工程质量检验评定标准》属于以下哪一类标准?A.综合基础标准 B.专业基础
心理学和生理学的研究证明,儿童智力发展的关键期是( )。A.婴儿期 B.学前
以下疾病可出现皮肤蜘蛛痣的是A.胃溃疡 B.再生障碍性贫血 C.地中海贫血
La4A4160继电保护装置试验分为三种,它们分别是()。(A)验收试验、
(2016年真题)根据生理效应,肾上腺素受体分为α受体和β受体,α受体分为α1、
青春期功能失调性子宫出血最常见的临床类型是A.无排卵性功血 B.有排卵性功血
最新回复
(
0
)