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
23
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.
There is more rainfall
选项
A over the mountains than over the rivers.
B over the rivers than over the mountains.
C over the oceans than over the land.
D over the land than over the oceans.
答案
D
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/BCsQKKKQ
相关试题推荐
共用题干 第二篇GoodTableMannersMannersplayanimportantpartinmakingafavorab...
共用题干 第二篇GoodTableMannersMannersplayanimportantpartinmakingafavorab...
共用题干 第二篇GoodTableMannersMannersplayanimportantpartinmakingafavorab...
共用题干 第二篇GoodTableMannersMannersplayanimportantpartinmakingafavorab...
共用题干 第二篇GoodTableMannersMannersplayanimportantpartinmakingafavorab...
AnimportantpartofthenationalgovernmentistheForeignService,abranch...
TheMeanhgofDreams 1Dreamsplayanimportantroleinourlives.Iftheyc...
TheMeanhgofDreams 1Dreamsplayanimportantroleinourlives.Iftheyc...
FoodSafetyandFoodborneIllness Foodsafetyisanincreasinglyimportant...
FoodSafetyandFoodborneIllness Foodsafetyisanincreasinglyimportant...
随机试题
Jaeger近视力表的检查距离为 A.10cm B.15cm C.20cm
对于土质渗透性较大、挖掘较深的基坑可采用基坑排水方法有()。
图所示某临时性屋架端节点的单齿连接,齿深范围内的弓形垂直面积为10400mm2。
目前我国的社会统计主要的负责部门是( )。
复牌时对已接受的申报实行集合竞价,只揭示集合竞价()。
图示四个悬臂梁中挠曲线是圆弧的为:
教师的专业素养包含先进的教育理念、良好的教育能力和一定的{____}。
教学媒体
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性:
女,39岁。上腹隐痛不适5个月。近1个半月加剧,服胃痛片后有所缓解,未见食欲下降,大便隐血试验(+++),胃肠道钡剂检查见胃窦部小弯侧黏膜纹理紊乱,胃壁僵...