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.