首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
Water The second most important constituent (构成成分)of the biosphere (生物圈)is...
Water The second most important constituent (构成成分)of the biosphere (生物圈)is...
admin
2020-12-24
64
问题
Water
The second most important constituent (构成成分)of the biosphere (生物圈)is liquid water. This can only exist in a very narrow range of temperatures, since water freezes at 0℃ and boils at 100℃. Life as we know it would only be possible on the surface of a planet which had temperatures somewhere within this narrow range.
The earth’s supply of water probably remains fairly constant in quantity. The total quantity of water is not known very accurately, but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers. Most of it is in the form of the salt water of the oceans — about 97 percent. The rest is fresh, but three-quarters of this is in the form of ice at the Poles and on mountains, and cannot be used by living systems until melted. Of the remaining fraction, which is somewhat less than one percent of the whole, there is 10 ?20 times as much stored underground water as there is actually on the surface. There is also a tiny, but extremely important fraction of the water supply which is present as water vapour in the atmosphere.
Water vapour in the atmosphere is the channel through which the whole water circulation (循环)of the biosphere has to pass. Water evaporated (蒸发)from the surface of the oceans,from lakes and rivers and from moist (潮湿的) earth is added to it. From it the
water comes out again as rain or snow, falling on either the sea or the land. There is, as might be expected,a more intensive evaporation per unit area over the sea and oceans than over the land, but there is more rainfall over the land than over the oceans, and the balance
is restored by the runoff from the land in the form of rivers.
Most of the fresh water on Earth
选项
A is stored underground.
B is in the form of ice at the Poles and on mountains.
C is found in rivers and lakes.
D comes from the rain.
答案
B
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/fdlQKKKQ
相关试题推荐
GoodTableManners Mannersplayanimportantpartinmakingafavorableimpr...
GoodTableManners Mannersplayanimportantpartinmakingafavorableimpr...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
RiseinNumberofCancerSurvivors Canceristhesecondleadingcauseofdea...
随机试题
对建筑的疏散楼梯进行工程验收时,下列关于疏散楼梯间检查的做法中,正确的有()
9、A.蟾酥中毒症状 B.乌头类中毒症状 C.黄药子中毒症状 D.马钱子中
通过对机械设备的危害因素进行全面分析,采用智能设计手段,使机器在整个寿命周期内发
该工程项目流水施工特点为()。
根据《中华人民共和国继承法》的规定,下列说法错误的是()。
研究人员比较了过去3.3万年以来生活在欧洲的人的骨骼变化情况,发现从1万年前的中
基础型课程
可转换债券的期限最短为1年,最长为6年,自发行结束之日起()后才能转换为公司股票。A.3个月B.6个月C.9个月D.1年
压缩机属于风机的一种,多作为气体动力用,但其排出气体压力较高(>350kPa)。按作用原理可分为容积式和透平式两大类。下列属于容积式压缩机的有()。A.活塞式
在加强党风廉政建设和反腐败斗争中,要坚持有腐必反、有贪必肃,巩固反腐败成果,构建( )的有效机制,为经济社会发展营造良好政治生态。A、不敢腐B、不能腐C、不