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.10 Most stones have capillary passages that suck salt water from the wet ground.Death Valleyprovides an ultra-dry atmosphere and high daily temperatures, which promote evaporationand the formation of salt crystals along the cracks or other openings within stones.Thesecrystals grow as long as salt water is available.Like tree roots breaking up a sidewalk, thegrowing crystals exert pressure on the rock and eventually pry the rock apart along planes of15 weakness, such as banding in metamorphic rocks, bedding in sedimentary rocks, orpreexisting or incipient fractions, and along boundaries between individual mineral crystalsor grains.Besides crystal growth, the expansion of halite crystals (the same as everydaytable salt) by heating and of sulfates and similar salts by hydration can contribute additionalstresses.A rock durable enough to have withstood natural conditions for a very long time in20 other areas could probably be shattered into small pieces by salt weathering within a fewgenerations.The dominant salt in Death Valley is halite, or sodium chloride, but other salts, mostlycarbonates and sulfates, also cause prying and wedging, as does ordinary ice.Weathering bya variety of salts, though often subtle, is a worldwide phenomenon.Not restricted to arid25 regions, intense salt weathering occurs mostly in salt-rich places like the seashore, near thelarge saline lakes in the Dry Valleys of Antarctica, and in desert sections of Australia, NewZealand, and central Asia.41.What is the passage mainly about?A.The destructive effects of salt on rocks.B.The impressive salt rocks in Death Valley.C.The amount of salt produced in Death Valley.D.The damaging effects of salt on roads and highways.42.The word "it" in line 9 refers toA.salty waterB.groundwater tableC.capillary actionD.sediment43.The word "exert" in line 14 is closest in meaning toA.putB.reduceC.replaceD.control44.In lines 13-17, why does the author compare tree roots with growing salt crystals?A.They both force hard surfaces to crack.B.They both grow as long as water is available.95Dedication Innovation ProfessionalismEQuest Academy Joint Stock CompanyAdd: 44 Hang Chao, Dongda, HanoiTel: 84-4-823 6151 Fax: 84-4-823 6151Email: EQA@EQuest.edu.vn Website: www.EQuest.edu.vnC.They both react quickly to a rise in temperature.D.They both cause salty water to rise from the groundwater table.45.In lines 17-18, the author mentions the "expansion of halite crystals.by heating and of sulfates and similar saltsby hydration" in order toA.present an alternative theory about crystal growthB.explain how some rocks are not affected by saltC.simplify the explanation of crystal prying and wedgingD.introduce additional means by which crystals destroy rocks46.The word "durable" in line 19 is closest in meaning toA.largeB.strongC.flexibleD.pressured47.The word "shattered" in line 20 is closest in meaning toA.arrangedB.dissolvedC.broken apartD.gathered together48.The word "dominant" in line 22 is closest in meaning toA.most recentB.most commonC.least availableD.least damaging49.According to the passage, which of the following is true about the effects of salts on rocks?A.Only two types of salts cause prying and wedging.B.Salts usually cause damage only in combination with ice.C.A variety of salts in all kinds of environments can cause weathering.D.Salt damage at the seashore is more severe than salt damage in Death Valley,50.Which of the following can be inferred from the passage about rocks that are found in areas where ice iscommon?A.They are protected from weathering.B.They do not allow capillary action of water.C.They show similar kinds of damage as rocks in Death Valley.D.They contain more carbonates than sulfates96Dedication Innovation ProfessionalismEQuest Academy Joint Stock CompanyAdd: 44 Hang Chao, Dongda, HanoiTel: 84-4-823 6151 Fax: 84-4-823 6151Email: EQA@EQuest.edu.vn Website: www.EQuest.edu.vnTHEME 7: THE DEVELOPMENT OF CITIES IN THE US97Dedication Innovation ProfessionalismEQuest Academy Joint Stock CompanyAdd: 44 Hang Chao, Dongda, HanoiTel: 84-4-823 6151 Fax: 84-4-823 6151Email: EQA@EQuest.edu.vn Website: www.EQuest.edu.vn1995-10Questions 14-22Mass transportation revised the social and economic fabric of theAmerican city in three fundamental ways.It catalyzed physical expansion, itsorted out people and land uses, and it accelerated the inherent instability ofurban life.By opening vast areas of unoccupied land for residential(5) expansion, the omnibuses, horse railways, commuter trains, and electrictrolleys pulled settled regions outward two to four times more distant fromcity centers than they were in the premodern era.In 1850, for example, theborders of Boston lay scarcely two miles from the old business district by theturn of the century the radius extended ten miles.Now those who could(10) afford it could live far removed from the old city center and still commutethere for work, shopping, and entertainment.The new accessibility of landaround the periphery of almost every major city sparked an explosion of realestate development and fulled what we now know as urban sprawl.Between1890 and 1920, for example, some 250,000 new residential lots were(15) recorded within the borders of Chicago, most of them located in outlyingareas.Over the same period, another 550,000 were plotted outside the citylimits but within the metropolitan area [ Pobierz całość w formacie PDF ]