Itisreportedthattheworld’spopulationwas6billionintheyear2,000,anditisgrowingfasterandfaster.Theworld’spopulationproblemisthegreatestonebecauseitbringslotsofproblems,suchaswaterresourcesproblem,moreandmorepeoplelosingtheirjobsandsoon.Theseproblemsaremainlyinthedevelopingcountriesbecausethepopulationofthedevelopingcountriesisover4/5oftheworld’spopuation.SoChina,thelargestdevelopingcountry,haskeptthepolicy“onecouple,onechild.”