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
In Death Valley, California, one of the hottest, most arid places in North America, there is much salt, and salt can damage rock
In Death Valley, California, one of the hottest, most arid places in North America, there is much salt, and salt can damage rock
admin
2014-01-13
76
问题
In Death Valley, California, one of the hottest, most arid places in North America, there is much salt, and salt can damage rocks impressively. Inhabitants of areas elsewhere, where streets and highways are salted to control ice, are familiar with the resulting rust and deterioration on cars. That attests to the chemically corrosive nature of salt, but it is not the way salt destroys rocks. Salt breaks rocks apart principally by a process called crystal prying and wedging. This happens not by soaking the rocks in salt water, but by moistening their bottoms with salt water. Such conditions exist in many areas along the eastern edge of central Death Valley. There, salty water rises from the groundwater table by capillary action through tiny spaces in sediment until it reaches the surface.
Most stones have capillary passages that suck salt water from the wet ground. Death Valley provides an ultra-dry atmosphere and high daily temperatures, which promote evaporation and the formation of salt crystals along the cracks or other opening within stones. These crystals grow as long as salt water is available. Like tree roots breaking up a sidewalk, the growing crystals exert pressure on the rock and eventually pry the rock apart along planes of weakness, such as banding in metamorphic rocks, bedding in sedimentary rocks, or preexisting or incipient fractions, and along boundaries between individual mineral crystals or grains. Besides crystal growth, the expansion of halite crystals(the same as everyday table salt)by heating and of sulfates and similar salts by hydration can contribute additional stresses. A rock durable enough to have withstood natural conditions for a very long time in other areas could probably be shattered into small pieces by salt weathering within a few generations.
The dominant salt in Death Valley is halite, or sodium chloride, but other salts, mostly carbonates and sulfates, also cause prying and wedging, as does ordinary ice. Weathering by a variety of salts, though often subtle, is a worldwide phenomenon. Not restricted to arid regions, intense salt weathering occurs mostly in salt-rich places like the seashore, near the large saline lakes in the Dry Valleys of Antarctica, and in desert sections of Australia, New Zealand, and central Asia.
The word "shattered" in line 20 is closest in meaning to______.
选项
A、arranged
B、dissolved
C、broken apart
D、gathered together
答案
C
解析
根据文章第二段最后一句“A rock durable enough to have withstood naturalconditions for a very long time in other areas could probably be shattered into small pieces by saltweathering within a few generations.”可知,在其他自然环境下,即使岩石具有持久的耐力,但是经过几代之后,也很有可能被盐风化成小碎片。从后面的small pieces,可知是broken apart。据此判断,答案是C。
转载请注明原文地址:https://kaotiyun.com/show/ebQO777K
0
考博英语
相关试题推荐
Atthefall2001SocialScienceHistoryAssociationconventioninChicago,theCrimeandJusticenetworksponsoredaforumonth
Youshouldspendnomorethan20minutesonthistask.Youandyourfamilyhaddinnerinarestaurantafewnightsago.The
In2007,IattendedtheTradeMinisters’meetinginBaliontherelationshipbetweentradeandclimatechange.InBali,Isenta
Heisamanobsessedbyhimself.Nottheslightestinterestwouldhehaveunlessitisamatterorpeopleconcerninghim.Tohim
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
Evenmorecrucially,theyaretheproductofanoutdatedpoliticalsystemwhichhasconsistentlysacrificedthelongtermtothe
AtatimeJaneAustin’snovelswerepublished--between181land1818--Englishliteraturewasnotpartofanyacademiccurriculum
Insuchachanging,complexsocietyformerlysimplesolutionstoinformationalneedsbecomecomplicated.Manyoflife’sproblems
Now,morethanever,itdoesn’tmatterwhoyouarebutwhatyoulooklike.Janetwasjusttwenty-fiveyearsold.Shehadag
TheBrownslivedina______andcomfortablyfurnishedhouseinthesuburbs.
随机试题
Inrecentyearsmanycountriesoftheworldhavebeenfacedwiththeproblemofhowtomaketheirworkersmoreproductive.Some
下列有关真核细胞mRNA的叙述,不正确的是
等渗性缺水多发生在
A.120~150℃,1~3sB.72~95℃,10~30sC.100~120℃,5~6sD.70~100℃,10~30sE.110~160℃,1~2s超高温瞬时灭菌法为
A.孕激素B.雌激素C.FSHD.LHE.雄激素有蛋白合成作用()
一舍饲牛,日粮以粗纤维饲料为主,一次过食后数小时,突发不安,后腿踢腹,不断摇尾,食欲废绝。临床检查,左腹部隆起,触诊坚实。检查瘤胃内容物,可能
A.合成尿素B.合成丙氨酸C.合成非必需氨基酸D.合成谷氨酰胺E.合成必需氨基酸骨骼肌中氨的主要运输形式是
经济适用住房的成本不包括()。
以下描述中,不属于汽车贷款特征的是()
一个TCP连接总是以1KB的最大段长发送TCP段,发送方有足够多的数据要发送。当拥塞窗口为16KB时发生了超时,如果接下来的4个RTT(往返时间)时间内的TCP段的传输都是成功的,那么当第4个RTT时间内发送的所有TCP段都得到肯定应答时,拥塞窗口大小是_
最新回复
(
0
)