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.

Marytiptoedoverandtooktheclockawaybecauseshehatedtohearit（）whenshewastryingtogotosleep.

Letchildrenlearntojudgetheirownwork.Achildlearningtotalkdoesnotlearnbybeingcorrectedallthetime;ifcorrectedtoomuch,hewillstoptalking.Henoticesathousandtimesadaythedifferencebetweenthelanguagesheusesandthelanguagethosearoundhimuse.Bitbybit,hemakesthenecessarychangestomakehislanguagelikeotherpeople.Inthesameway,whenchildrenlearntodoalltheotherthingstheylearntodowithoutbeingtaught-towalk,run,climb,whistle,rideabicycle-comparethoseperformanceswiththoseofmoreskilledpeople,andslowlymaketheneededchanges.Butinschoolwenevergiveachildachancetofindouthisownmistakesforhimself,letalonecorrectthem.Wedoitallforhim.Weactasifwethoughtthathewouldnevernoticeamistakeunlessitwaspointedouttohim,orcorrectitunlesshewasmadeto.Soonhebecomesdependentontheteacher.Lethimdoithimself.Lethimworkout,withthehelpofotherchildrenifhewantsit,whatthiswordsays,whatansweristothatproblem,whetherthisisagoodwayofsayingordoingthisornot.

Ifitisamatterofrightanswers,asitmaybeinmathematicsorscience,givehimtheanswerbook.Lethimcorrecthisownpapers.Whyshouldweteacherswastetimeonsuchroutinework?Ourjobshouldbetohelpthechildwhenhetellsusthathecan’tfindthewaytogettherightanswer.Let’sendthisnonsenseofgrades,exams,marks,Letusthrowthemallout,andletthechildrenlearnwhatalleducatedpersonsmustsomedaylearn,howtomeasuretheirownunderstanding,howtoknowwhattheyknowordonotknow.

Letthemgetonwiththisjobinthewaythatseemssensibletothem.Withourhelpasschoolteachersiftheyaskforit.Theideathatthereisabodyofknowledgetobelearntatschoolandusedfortherestofone’slifeisnonsenseinaworldascomplicatedandrapidlychangingasours.Anxiousparentsandteacherssay,“Butsupposetheyfailtolearnsomethingessentialtheywillneedtogetintheworld?”Don’tworry!Ifitisessential,theywillgooutintotheworldandlearnit.

1.Whatdoestheauthorthinkisthebestwayforchildrentolearnthings?

A.bycopyingwhatotherpeopledo.

B.bymakingmistakesandhavingthemcorrected.

C.bylisteningtoexplanationsfromskilledpeople.

D.byaskingagreatmanyquestions.

2.Whatdoestheauthorthinkteachersdowhichtheyshouldnotdo?

A.Theygivechildrencorrectanswers.

B.Theypointoutchildren’smistakestothem.

C.Theyallowchildrentomarktheirownwork.

D.Theyencouragechildrentomarktocopyfromoneanother.

3.Thepassagesuggeststhatlearningtospeakandlearningtorideabicycleare___.

A.notreallyimportantskills.

B.moreimportantthanotherskills.

C.basicallydifferentfromlearningadultskills.

D.basicallythesameaslearningotherskills.

4.Exams,grades,andmarksshouldbeabolishedbecausechildren’sprogressshouldonlybeestimatedby___.

A.educatedpersons.

B.thechildrenthemselves.

C.teachers.

D.parents.

5.Theauthorfearsthatchildrenwillgrowupintoadultswhilebeing___.

A.tooindependentofothers.

B.toocriticalofthemselves.

C.incapabletothinkforthemselves.

D.incapabletousebasicskills.

Evenifhisletter____tomorrow，it____toolatetodoanything.

Ineverregretted_____hisoffer,foritwasnotwheremyinterestlay.