in rcnt yars, mor and mor migrant workrs hav movd into big citis and thy hav bn making grat contributions to th dvlopmnt of citis. nw buildings nd thm, roads can't b rpaird without thm, and th planting and protcting of trs and flowrs dpnd on thm. indd, thy play an important rol in th construction of citis in china today.howvr, thy hav brought about som problms. th biggst on is th incras of th city population. th onc crowdd citis hav now bcom mor crowdd. and thir arrival may caus a srious crisis in housing, watr and othr rsourcs. in addition, thy hav takn so many jobs that th labor markt in citis has bcom vn wakr. what's mor, som of th farmland is lft uncultivatd as a rsult of th farmrs' migration.in my opinion, migrant workrs' contributions outwigh th inconvnincs thy bring us. on th whol, thy hav bcom an important part of our socialist buildrs. nvrthlss, th govrnmnt should work out nw policis to control th migration of farmrs on th on hand and to protct migrant workrs' rights and intrsts on th othr hand.