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
55
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
Despite(1)thatalcoholicbeveragesmay(2),aleadingmedicalexpertisa
Inthefirstincident,thecouplehadplannedtospendtheirweekendtogether__
旗袍(cheong—Sam)源自清代满族(Manchu)女性服饰,被誉为中国传统服饰(habilatory)文化的典范。它不仅在整体造型的风格方面符合中
第一代工业设计师产生于美国,时间大约是在20世纪()年代前后。A.20 B.3
无线电通信,存在易于截获、窃听等问题,对重要保密通信,应采取终端保密措施。
对于商业、旅游、娱乐、商业住宅等经营性用地,一般应该采用( )方式获取土地使用
生产商甲在销售商品给销售商乙时,限定乙将商品转售给第三人的单价不得低于500元。
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
某工程主体结构混凝土工程量为3200m3,预算单价为550元/m3,计划4个月内
管道进行气压试验的正确步骤是( )。A.缓慢升压至试验压力的30%→按试验压力
最新回复
(
0
)