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
4
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、They have very few hairs on their bodies.
B、They bear their young rather than laying eggs.
C、Their lungs are full of hot air and water.
D、They can walk on their hind legs on land.
答案
A
解析
细节题。根据原文中的最后一句话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.(除了人以外,几乎所有的陆地哺乳动物都靠身上的毛取暖。而鲸鱼身上几乎没有毛,是靠它们的脂肪取暖。)可知,鲸和其他哺乳动物的区别在于取暖方式不同。选项A同原文的意思一致。B、C、D选项在
转载请注明原文地址:https://tihaiku.com/zcyy/3611506.html
相关试题推荐
[originaltext]M:Whydoyouthinkthatway?W:WhileIadmitthereisverylitt
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]M:IjustwonderwhyJanetneverbecomesanactressintheadvert
[originaltext]Millionsofyearsago,whaleslivedonlandandwalkedonfo
[originaltext]Millionsofyearsago,whaleslivedonlandandwalkedonfo
[originaltext]Millionsofyearsago,whaleslivedonlandandwalkedonfo
[originaltext]Millionsofyearsago,whaleslivedonlandandwalkedonfo
[originaltext]Itisagreatprivilegeformetobeinvitedtospeakatthe
[originaltext]Itisagreatprivilegeformetobeinvitedtospeakatthe
随机试题
下列关于室内消火栓设备的安装布置要求说法正确的是()。A.设置室内消火栓的建筑
假定一棵度为3的树中结点数为50,则其最小高度应为()。A.5 B.6 C.
下列选项中,属于《证券投资基金法》立法宗旨的有( )。 ①促进证券投资基金和
A.圣愈汤 B.升举大补汤 C.举元煎 D.补中益气汤 E.补气通脬饮治
A.防风、防己B.柴胡、胡黄连C.猪苓、茯苓D.生龙骨、生牡蛎E.煅龙骨、煅牡蛎
将一长度为L的线段任意截成三段,设p1为所截的三线段能构成三角形的概率,p2为所
2月11日晚,北京冬奥会男子钢架雪车第三、第四轮的比赛在延庆赛区的国家雪车雪橇中
下列不是经营机构向普通投资者销售产品时,应当告知的信息( )A.因经营机构的基层
某男,20岁。平日喜食冷饮,近日胃痛,大便稀溏,此患者的证候禁忌是A.忌用开窍药
老年人高血压的特点,下列那项不符合 A血压波动小B容易发生心功能不全C
最新回复
(
0
)