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
53
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
Whenmostpeoplethinkaboutchangingtheirbodyshape,theyusuallyfocusonjustlosingweight.Booksandmagazinesaboutdiet
Studentsofthegreatsociety,lookingatmankindinthelongperspectiveofhistory,havefrequentlybeendisposedtoseekane
Animportantconsequencearisesbecausethesocialsecurityprogramispurelypay-as-you-gofinanced,_____mostpensionplans,at
Chooseoneappropriatewordfromthefollowingwordbanktofillintheblanknumberedfrom91to105inthepassagebelow.Chan
AstoutoldladywaswalkingwithherbasketdownthemiddleofastreetinPetrogradtothegreatconfusionofthetrafficand
Giventhelackoffitbetweengiftedstudentsandtheirschools,itisnotsurprisingthatsuchstudentsoftenhavelittlegood
Thesecontinual______intemperaturemakeitimpossibletodecidewhattowear.
Thelong-termfortunesofthemodemeconomydependinpartonthestrengthandsustainabilityofthefamily,bothinrelationto
一位负责扶贫工作的官员说,到2004年底,尽管大多数贫困人口将解决温饱问题,还将有一些生活极端贫困的人们,他们还需要政府资助。此外,对于那些刚刚脱贫的人们,他们目前的生活状况必须改善,因为他们的生产和生活状况没有从根本上被改变。如果遭受自然灾害的袭击,就可
again本题空格处是说黄昏时家人们再次聚在一起。onceagain意为“再一次”。
随机试题
A.病变累及左颈部淋巴结区B.病变累及右侧颈、腋下和腹股沟淋巴结C.病变累及左腋下淋巴结及肝脏D.病变累及右锁骨上及左颈部淋巴结E.病变累及左颈和纵隔淋巴结及左肺限局浸润Ⅳ期淋巴瘤
分配系数的测定可用于预测同系列化合物的体内吸收情况。()
某患者,女性,17岁,两周前感冒,一天来胸闷、气短、头晕、行走时眼前发黑。查体:BP85/50mmHg,心律不齐,心率36次/分,心电图示三度房室传导阻滞,多源性室性,应选用的最佳治疗方案为
根据《中药品种保护条例》,2013年有6家企业生产的“复方大青叶合剂”获批为国家中药保护品种,保护期限为7年。下列关于复方大青叶合剂的中药品种保护的说法,正确的有
下列贷款重组方式中,不属于变更担保条件的是()。
公司持有的本公司股份不得分配利润。()
以下属于皇家园林的是()。
TheChinaboomisbynowawell-documentedphenomenon.Whohasn’t【1】theMiddleKingdom’sastoundingeconomicgrowth8percentan
请根据以下各小题的要求设计VisualBasic应用程序(包括界面和代码)。(1)在名称为Forml的窗体上画两个命令按钮,其名称分别为Commandl和Command2,标题分别为“扩大”和“移动”。如图2.236所示,编写适当的事件过程。程
已知函数print0没有返回值,如果在类中将之声明为常成员函数,正确的是()。
最新回复
(
0
)