三氧化硫极易吸水,在空气中强烈发烟;溶于水形成硫酸,溶于浓硫酸形成发烟硫酸,并产生大量溶解热。

更新时间:2024-10-30 03:27:11
1、正确
2、错误
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正确

答案解析:

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There_____nothingmorefordiscussion,themeetingcametoanendhalfanearlier.

A、tobe
B、tohavebeen
C、being
D、be

Wecanbeginourdiscussionof“populationasglobalissue”withwhatmostpersonsmeanwhentheydiscuss“thepopulationproblem”:toomanypeopleonearthandatoorapidincreaseinthenumberaddedeachyear.Thefactsarenotindispute,Itwasquiterighttoemploytheanalogythatlikeneddemographicgrowthto“along,thinpowderfusethatburnssteadilyandhaltinglyuntilitfinallyreachesthechargeandexplodes.”

Tounderstandthecurrentsituation,whichischaracterizedbyrapidincreasesinpopulation,itisnecessarytounderstandthehistoryofpopulationtrends.Rapidgrowthisacomparativelyrecentphenomenon.Lookingbackatthe8,000yearsofdemographichistory,wefindthatpopulationshavebeenvirtuallystableorgrowingveryslightlyformostofhumanhistory.Formostofourancestors,lifewashard,oftennasty,andveryshort.Therewashighfertilityinmostplaces,butthiswasusuallybalancedbyhighmortality.Formostofhumanhistory,itwasseldomthecasethatoneintenpersonswouldlivepastforty,whileinfancyandchildhoodwereespeciallyriskyperiods.Often,societieswereincleardangerofextinctionbecausedeathratescouldexceedtheirbirthrates.Thus,thepopulationproblemthroughoutmostofhistorywashowtopreventextinctionofthehumanrace.

Thispatternisimportanttonotice.Notonlydoesitputthecurrentproblemsofdemographicgrowthintoahistoricalperspective,butitsuggeststhatthecauseofrapidincreaseinpopulationinrecentyearsisnotasuddenenthusiasmformorechildren,butanimprovementintheconditionsthattraditionallyhavecausedhighmortality.

Demographichistorycanbedividedintotwomajorperiods:atimeoflong,slowgrowthwhichextendedfromabout8,000BC.tillapproximatelyAD.1650.Inthefirstperiodofsome9600years,thepopulationincreasedfromsome8millionto500millionin1650.Between1650andthepresent,thepopulationhasincreasedfrom500milliontomorethan4billion.Anditisestimatedthatbytheyear2000therewillbe6.2billionpeoplethroughouttheworld.Onewaytoappreciatethisdramaticdifferenceinsuchabstractnumbersistoreducethetimeframetosomethingthatismoremanageable.Between8000BCand1650,anaverageofonly50,000personswasbeingaddedannuallytotheworld’spopulationeachyear.Atpresent,thisnumberisaddedeverysixhours.Theincreaseisabout80,000,000personsannually.

1.Whichofthefollowingdemographicgrowthpatternismostsuitableforthelongthinpowderfuseanalogy?

A.Avirtuallystableorslightlydecreasingperiodandthenasuddenexplosionofpopulation.

B.Aslowgrowthforalongtimeandthenaperiodofrapid,dramaticincrease.

C.Toomanypeopleonearthandafewrapidincreaseinthenumberaddedeachyear.

D.Alongperiodwhendeathratesexceedsbirthratesandthenashortperiodwithhigherfertilityandlowermortality.

2.Duringthefirstperiodofdemographichistory,societieswereoftenindangerofextinctionbecause___.

A.onlyoneintenpersonscouldlivepast40.

B.therewashighermortalitythanfertilityinmostplaces.

C.itwastoodangeroustohavebabiesduetothepoorconditions.

D.ourancestorshadlittleenthusiasmformorechildren.

3.Whichstatementistrueaboutpopulationincrease?

A.Theremightbeanincreaseof2.2billionpersonsfromnowtotheyear2000.

B.About50,000babiesareborneverysixhoursatpresent.

C.Between8000BCandthepresent,thepopulationincreaseisabout80,000,000personseachyear.

D.Thepopulationincreasedfasterbetween8000BCand1650thanbetween1650andthepresent.

4.Theauthorofthepassageintendsto___.

A.warnpeopleagainstthepopulationexplosioninthenearfuture.

B.comparethedemographicgrowthpatterninthepastwiththatafter1650.

C.findoutthecauseforrapidincreaseinpopulationinrecentyears.

D.presentusaclearandcompletepictureofthedemographicgrowth.

5.Theword“demographic”inthefirstparagraphmeans___.

A.statisticsofhuman.

B.surroundingsstudy.

C.accumulationofhuman.

D.developmentofhuman.

翻译训练:普通话与方言

中国土地广阔,人口众多。尽管全国都讲汉语,但是不同地区的人说汉语的方式不同,这被称为方言。方言一般被称为地方话,是汉语在不同地区的分支,只在特定地区使用。汉语方言非常复杂。它们有以下三方面不同:发音、词汇和语法。发音的区别最为显著。2000多年前,中国人发现社交时应该使用统一的语言。和方言相比,普通话(mandarin)能被所有人理解。普通话有利于不同种族、地区人民之间的信息传递和文化交流。

Evenifhisletter()tomorrow,it()toolatetodoanything.

A、willarrive,,is
B、shouldarrive,,were
C、arrives,,willbe
D、arrives,,wouldbe

PARTVREADINGCOMPREHENSION

Inthissectiontherearefourpassagesfollowedbyquestionsorunfinishedstatements,eachwithfoursuggestedanswersmarkedA,B,CandD.Choosetheonethatyouthinkisthebestanswer.

TEXTA

Racket,dinclamor,noise,whateveryouwanttocallit,unwantedsoundisAmerica'smostwidespread

nuisance.Butnoiseismorethanjustanuisance.Itconstitutesarealandpresentdangertopeople'shealth.Day

andnight,athome,atwork,andatplay,noisecanproduceseriousphysicalandpsychologicalstress.Nooneis

immunetothisstress.Thoughweseemtoadjusttonoisebyignoringit,theear,infact,neverclosesandthe

bodystillresponds—sometimeswithextremetension,astoastrangesoundinthenight.

Theannoyancewefeelwhenfacedwithnoiseisthemostcommonoutwardsymptomofthestressbuilding

upinsideus.Indeed,becauseirritabilityissoapparent,legislatorshavemadepublicannoyancethebasisof

manynoiseabatementprograms.Themoresubtleandmoreserioushealthhazardsassociatedwithstress

causedbynoisetraditionallyhavebeengivenmuchlessattention.Nevertheless,whenweareannoyedormade

irritablebynoise,weshouldconsiderthesesymptomsfairwarningthatotherthingmaybehappeningtous,

someofwhichmaybedamagingtoourhealth.

Ofmanyhealthhazardstonoise,hearinglossisthemostclearlyobservableandmeasurablebyhealth

professionals.Theotherhazardsarehardertopindown.Formanyofus,theremaybeariskthatexposuretothe

stressofnoiseincreasessusceptibilitytodiseaseandinfection.Themoresusceptibleamongusmayexperience

noiseasacomplicatingfactorinheartproblemsandotherdiseases.Noisethatcausesannoyanceandirritability

inhealthpersonsmayhaveseriousconsequencesforthesealreadyillinmindorbody.

Noiseaffectsusthroughoutourlives.Forexample,thereareindicationsofeffectsontheunbornchildwhen

mothersareexposedtoindustrialandenvironmentalnoise.Duringinfancyandchildhood,youngstersexposed

tohighnoiselevelsmayhavetroublefallingasleepandobtainingnecessaryamountsofrest.

Why,then,istherenotgreateralarmaboutthesedangers?Perhapsitisbecausethelinkbetweennoiseand

manydisabilitiesordiseaseshasnotyetbeenconclusivelydemonstrated.Perhapsitisbecausewetendto

dismissannoyanceasapricetopayforlivinginthemodernworld.Itmayalsobebecausewestillthinkof

hearinglossasonlyanoccupationalhazard.

1.InParagraph1,thephrase"immuneto"areusedtomean___.

A.unaffectedby

B.hurtby

C.unlikelytobeseenby

D.unknownby

2.Theauthor'sattitudetowardnoisewouldbestbedescribedas___.

A.unrealistic

B.traditional

C.concerned

D.hysterical

3.Whichofthefollowingbeststatesthemainideaofthepassage?

A.Noiseisamajorproblem;mostpeoplerecognizeitsimportance.

B.Althoughnoisecanbeannoying,itisnotamajorproblem.

C.Noiseisamajorproblemandhasnotyetbeenrecognizedassuch.

D.Noiseisamajorproblemaboutwhichnothingcanbedone.

4.Theauthorcondemnsnoiseessentiallybecauseit___.

A.isagainstthelaw

B.canmakesomepeopleirritable

C.isanuisance

D.inagangertopeople'shealth

5.Theauthorwouldprobablyconsiderresearchabouttheeffectsnoisehasonpeopletobe___.

A.unimportant

B.impossible.

C.awasteofmoney

D.essential

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