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
5
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://www.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
[originaltext]Formostpeople,readinganewspaperhasbecomeahabitpasse
Howmenfirstlearnedtoinventwordsisunknown;inotherwords,theorigin
Schoolsoutsidecities[A]Withitssandybeaches,charm
[originaltext]TheBritishIslescanbedividedintotwo,notonlybecauseo
肛裂“三联征”指的是()A.内痔,外痔,肛裂 B.肛裂,前哨痔
填制原始凭证时应符合的一般要求有()。A.记录真实 B.手续完备 C.内容齐
根据《建筑施工企业安全生产许可证管理规定》,下列选项中说法正确的有()。A、安全
照明系统全面巡视应包含()(A)照明灯杆完好(B)灯杆无歪斜、锈蚀,基础完
特雷诺指数是()。A:连接证券组合与无风险资产的直线的斜率B:连接证券组合与无
关于建设工程施工文件归档质量要求的说法,正确的有( )。A.归档文件用原件和复
最新回复
(
0
)