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
43
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.
The total quantity of water on Earth
选项
A remains almost unchanged.
B has greatly increased in recent years.
C is decreasing constantly.
D is affected by global warming
答案
A
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/NnsQKKKQ
相关试题推荐
ShoppingatSecond-handClothingStores When33-year-oldPeteBarthwasin...
ShoppingatSecond-handClothingStores When33-year-oldPeteBarthwasin...
共用题干 第一篇WaterResourcesontheEarthThesecondmostimportantconstituent(构成...
共用题干 第一篇WaterResourcesontheEarthThesecondmostimportantconstituent(构成...
共用题干 第一篇WaterResourcesontheEarthThesecondmostimportantconstituent(构成...
共用题干 第二篇WhyNotEatBreakfast?Breakfastisnotonlythemostimportantmeal...
共用题干 第二篇WhyNotEatBreakfast?Breakfastisnotonlythemostimportantmeal...
共用题干 第二篇WhyNotEatBreakfast?Breakfastisnotonlythemostimportantmeal...
共用题干 第二篇WhyNotEatBreakfast?Breakfastisnotonlythemostimportantmeal...
共用题干 第二篇GoingHerOwnWayWhenshewastwelve,Mariamadeherfirstimportant...
随机试题
在使用中对水泥质量有怀疑或水泥出厂超过( )个月时,应进行复验,并按复验结果使
根据资产评估报告中评估基准日时点选择上的差异,资产评估报告可以划分的类型有()。
局部不良反应包括()。 A.血肿 B.头晕 C.虚汗 D.恶心 E.呕
激光焊接时后一个焊点应覆盖前一个焊点的 A.50% B.70% C.60%
假设检验的基本思想是反证法和小概率思想。()
根据《建筑工程施工质量验收同意标准》,下列工程中,属于分部工程的有( )。
会计的基本职能包括()。
猪苓区别于茯苓粉末的主要显微特征是A:有菌丝团B:有无色菌丝C:有色菌丝D:有草酸钙晶体E:有淀粉粒
依据《生产安全事故信息报告和处置办法》,生产经营单位对较大涉险事故迟报、漏报、谎报或者瞒报的,给予警告,并处()以下的罚款。A.5000元B.1万元C.
国际法院就甲、乙两国的争议作出裁决后,甲国拒不履行判决确定的义务。依《国际法院规约》的规定,对此下列哪一说法是正确的?()A.乙国可向联合国安理会提出申诉,请