首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The geology of the Earth’s surface is dominated by the particular properties of water. Present on Earth in solid, liquid, and ga
The geology of the Earth’s surface is dominated by the particular properties of water. Present on Earth in solid, liquid, and ga
admin
2016-02-26
48
问题
The geology of the Earth’s surface is dominated by the particular properties of water. Present on Earth in solid, liquid, and gaseous states, water is exceptionally reactive. It dissolves, transports, and precipitates many chemical compounds and is constantly modifying the face of the Earth.
Evaporated from the oceans, water vapor forms clouds, some of which are transported by wind over the continents. Condensation from the clouds provides the essential agent of continental erosion: rain. Precipitated onto the ground, the water trickles down to form brooks, streams, and rivers, constituting what is called the hydrographic network. This immense polarized network channels the water toward a single receptacle: an ocean. Gravity dominates this entire step in the cycle because water tends to minimize its potential energy by running from high altitudes toward the reference point that is sea level.
The rate at which a molecule of water passes through the cycle is not random but is a measure of the relative size of the various reservoirs. If we define residence time as the average time for a water molecule to pass through one of the three reservoirs—atmosphere, continent, and ocean—we see that the times are very different. A water molecule stays, on an average, eleven days in the atmosphere, one hundred years on a continent and forty thousand years in the ocean. This last figure shows the importance of the ocean as the principal reservoir of the hydrosphere but also the rapidity of water transport on the continents.
A vast chemical separation process takes places during the flow of water over the continents. Soluble ions such as calcium, sodium, potassium, and some magnesium are dissolved and transported. Insoluble ions such as aluminum, iron, and silicon stay where they are and form the thin, fertile skin of soil on which vegetation can grow. Sometimes soils are destroyed and transported mechanically during flooding. The erosion of the continents thus results from two closely linked and interdependent processes, chemical erosion and mechanical erosion. Their respective interactions and efficiency depend on different factors.
The word "efficiency" in line 21 is closest in meaning to______.
选项
A、relationship
B、growth
C、influence
D、effectiveness
答案
C
解析
词义推断题。选项effectiveness与efficiency词根相同,由此可知答案为C。
转载请注明原文地址:https://kaotiyun.com/show/YHGO777K
0
考博英语
相关试题推荐
democracyovercomemodernplaceanticipateimaginationonlineregularperformaccessdif
Thebasiccausesareunknown,althoughcertainconditionsthatmayleadtocancerhavebeen______.
Inmoderndays,onthewesternbankoftheupperTigrisRiverstandsanIraqicitycalledQal’atShartlat.Thousandsofyearsag
Whowouldhavethoughtwewouldbecomeaplanetof"ologies"?There’sbiology,psychology,herpetology,etymology,andgeologyj
Itisdevelopingaservicethatwillletyoucreateallonlineidentitythatcan______variousclaimsthatitwillbackup.
ThereismuchIenjoyaboutthechangingseasons,butmyfavoritetimeisthe______fromfalltowinter.
TheFrencheducationsystemisverydifferentfromtheEnglishoneinitsaims,itsorganizationanditsresults.TheFrenchchi
Mostworthwhilecareersrequiresomekindofspecializedtraining.Ideally,therefore,thechoiceofan【C1】______shouldbemade
Asianeconomiccrisishasonlya_______effectonthelivesofChinesepeople.
在中美两国政府的共同支持下,美国的学校开始在语言教学大纲巾增设汉语——这个世界上使用人数多但同时也是最难学的语言之一。在2400所学校表示有兴趣之后,将于明年开始在全国范围内的中学开设汉语高级分级课程。因此全美国范围内的汉语语言课程,包括小学到成人教育,在
随机试题
以下选项中,不符合基金管理公司组织结构相互制约的是()。
在较大规模的调查中,对于需要相互比较的材料,要审核其所涉及的事实是不是具有可比性。这是遵守资料审核的()
在空间中,方程y=x2表示()
下列选项中,不属于间接补偿的是()。
当计算进口设备的消费税时,计算基础中应该包括()。
为了迅速取得资料,并且在经济活动中及时采取措施进行调整,则需要进行( )。
在财务评价中,应计入经营成本的费用是()。
“蓬生麻中,不扶自直;白沙在涅,与之俱黑”反映了()对人的发展有重要影响。
不属于我国学校德育基本内容的是
Apenguin—thatblackandwhitebirdcameashoreonabeachinthesouthoftheNorthIslandnearly4000milesawayfromitsusu
最新回复
(
0
)