首页
登录
职称英语
[originaltext] Millions of years ago, whales lived on land and walked on fo
[originaltext] Millions of years ago, whales lived on land and walked on fo
游客
2024-05-30
58
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.
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 cold water.(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/3611505.html
相关试题推荐
[originaltext]M:Whydoyouthinkthatway?W:WhileIadmitthereisverylitt
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]Millionsofyearsago,whaleslivedonlandandwalkedonfo
[originaltext]Millionsofyearsago,whaleslivedonlandandwalkedonfo
[originaltext]Iwillletyouknowthatthere’sabigdifferencebetweenun
[originaltext]Iwillletyouknowthatthere’sabigdifferencebetweenun
[originaltext]Itisagreatprivilegeformetobeinvitedtospeakatthe
随机试题
Duringrecentyearswehaveheardmuchabout"race":howthisracedoescert
[originaltext]Cultureshockcanbedescribedasthefeelingofconfusionan
据可靠数据,中国餐饮业2012年一年浪费的食物相当于两亿多人一年的口粮。面对严重的食物浪费,北京一家民间公益组织利用微博发起了一项反对浪费的行动一一“光
Shoalsoffishareabletomoveandturninseamlessformationbyfollowing
A.灰黄色~黄色B.黄~橙黄色C.无色D.微黄色E.橘黄色查耳酮颜色通常为
投资者目前持有一期权,其有权选择在到期日之前的任何一个交易日卖或不卖2000份美
人性具有( )A.能动性 B.社会性 C.整体性 D.两面性 E.可变
地基处理时,对处理范围的叙述()是不正确的。 A.砂石桩处理范围应大于基础范围
下列各项中,企业编制合并财务报表时,需要进行抵销处理的有( )。A.母公司对子公
下列选项中,项目监理机构不可按()设立直线制监理组织形式。A.子项目分解
最新回复
(
0
)