lookatyourwatchforjustoneminuite.Duringthattime,Thepopuiationoftheworldincreasedby259.Perhapsyouthinkthatisnotmuch.Hoever,duringthenexthour,over15540morebabieswillbebornontheworld. 　　Soitgoeson,hourafterhour.Inoneday,peoplehavetoproducefoodfover370000moremouths.Multiplythisby365.justthinkhowmanymoretherewillbeinoneyear!Whatwillhappeninahundredyears? 　　Theincreasingpopulation 　　maybethegreatestchallengeoftheworldtoday.Theworld'spopulationisgrowingfasterandfaster.Twothousangyearsago,thereonly250millonpeopleontheearth.Atthebeiningofthe20thcentury,theworld'spopulationwasabout1.7billion.In1990,itreachedmorethanfivebillion.Nowatthebeininjgofthe21stcenttheworld'spopulationhaspassedsixbillion.peoplesaythatbytheyeay2010itmaybesevenbillion.Thatmeansinabout600years,therewillbrstandingroomonlyontheearth.Eachpersonwillhaveonehalftoonesquaremetreofspacetolivein.Therewillbehardlyenoughspacerorangbodyelse. 　　我终于打完了,累死偶了!@_@~没有功劳也有苦劳呀!