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
2017-06-30
57
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.
According to the passage, clouds are primarily formed by water______.
选项
A、precipitating onto the ground
B、changing from a solid to a liquid state
C、evaporating from the oceans
D、being carried by wind
答案
C
解析
定位第二段第一句“Evaporated from…the continents”可得知,云是蒸发后形成,故答案为C。
转载请注明原文地址:https://kaotiyun.com/show/wSFO777K
0
考博英语
相关试题推荐
Inadditiontoredistributingincomes,inflationmayaffectthetotalrealincomeandproductionofthecommunity.Anincreasein
Therearethreeseparatesourcesofhazard【C1】______totheuseofnuclearreactiontosupplyuswithenergy.Firstly,theradioa
Therearethreeseparatesourcesofhazard【C1】______totheuseofnuclearreactiontosupplyuswithenergy.Firstly,theradioa
Becausealcoholisasolvent,itisacomponentofmanyliquidmedicines.
Tosomepeople,thegreatestpleasureoflifeistospendtheirtimeathomewatchingTVand____theirpets.
Inthesimplestterms,amarketistheplacewheresellermeetsbuyertoexchangeproductsformoney.Traditionalmarketsstill
Everymorning,Alliewakesupandaccompaniesherfriendtothewashroom.Sheturnsonthelight,soapsupawashcloth,andbegi
Onbehalfofmycompany,Iam____toyouandyourcolleaguesforyourgeneroushelp.
Hisattitudetowardsocialwelfarelegislation,basedentirelyonhisperceptionofhimselfasaself-mademan,______himthesu
Somepundits______thatmanycomputersareobsoletebeforethey’reevendesigned,whichgoesalongwaytowardexplainingwhythe
随机试题
集中火灾报警控制器使用主电源工作时,主电源指示灯为红色。()
女性,25岁。无明显诱因月经量增多2个月,出现牙龈出血2天入院,既往体健。查体:胸腹部及四肢皮肤散在出血点和少量瘀斑,浅表淋巴结不大,牙龈少量渗血,心肺腹检查未见明显异常。化验血:Hb100g/L,RBC3.3×1012/L,WBC8.2×109/L,
甲杀人案,犯罪手段残忍,影响恶劣,第一审法院为防止被害人家属和旁听群众在法庭上过于激愤影响顺利审判,决定作为特例不公开审理。经审理,第一审法院判处甲死刑立即执行,甲上诉。对于本案,第二审法院下列哪些做法是正确的?
柯某长期打骂家人、为害乡邻,在当地激起民众公愤。其父屡次规劝柯某无果,决定大义灭亲。一日凌晨,柯某父亲在确认儿子熟睡后,用刀将儿子砍死,随后投案自首。当地乡民闻讯后联名请求司法机关对柯某父亲从轻处理。法院最后以故意杀人罪判处柯某父亲有期徒刑3年,缓刑5年。
函数f(x,y)在点P0(x0,y0)处有一阶偏导数是函数在该点连续的()。
在幻灯片母版中输入“你好中国”和插入图片,如图所示。当关闭母版后,原幻灯片()。
公安工作必须接受党的直接领导。()
外资金融机构在华代表处不得从事任何直接盈利的业务活动。()
设事件A与B独立且不相容,则min[P(A),P(B)]=_______.
计算并填写下表。
最新回复
(
0
)