inrecentyears,moreandmoremigrantworkershavemovedintobigcitiesandtheyhavebeenmakinggreatcontributionstothedevelopmentofcities.newbuildingsneedthem,roadscan'tberepairedwithoutthem,andtheplantingandprotectingoftreesandflowersdependonthem.indeed,theyplayanimportantroleintheconstructionofcitiesinchinatoday. 　　however,theyhavebroughtaboutsomeproblems.thebiggestoneistheincreaseofthecitypopulation.theoncecrowdedcitieshavenowbecomemorecrowded.andtheirarrivalmaycauseaseriouscrisisinhousing,waterandotherresources.inaddition,theyhavetakensomanyjobsthatthelabormarketincitieshasbecomeevenweaker.what'smore,someofthefarmlandisleftuncultivatedasaresultofthefarmers'emigration. 　　inmyopinion,migrantworkers'contributionsoutweightheinconveniencestheybringus.onthewhole,theyhavebecomeanimportantpartofoursocialistbuilders.nevertheless,thegovernmentshouldworkoutnewpoliciestocontroltheemigrationoffarmersontheonehandandtoprotectmigrantworkers'rightsandinterestsontheotherhand.