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
58
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
贵州的少数民族人口数量居全国第( )位。 A、一 B、二 C、三 D、
(3-4题共用题干) 患者男性,46岁,因顽固性呃逆就诊。医生给药后,呃逆缓解
关于非处方药叙述正确的是 A、仅针对医师等专业人员作适当的宣传介绍 B、目
期货合约的交割地点是由交易双方协商确定的。()
薪酬调查过程中,确定被调查的岗位时应当遵循()的原则。
2008年,生产该型号职员椅5000把,若获得同样多的利润,2006
某晚会计划设置抽奖环节,能用于购买奖品的总金额固定,且要求每名一等奖奖品的金额是
下列各项中,桃核承气汤的临床表现不包括
学生对知识的内在加工过程包括()。 A.知识的获得B.知识应用 C.知识巩固D.知识编码 E.知识提取
合同公证的内容不包括()。A.对当事人之间签订合同行为的真实性、合法性进行公证B.对当事人所签订的合同的真实性、合法性进行公证C.审查合同的内容是否符合国家