专题：任务型阅读一、填空Atthemoment,itmaybedifficulttoimagine,butmanypeoplebelievethat,bytheyear2100,wewillliveontheplanetMars．Ourownplanet,Earth,isbecomingmoreandmorecrowdedandpolluted．Luckily,wecanstartagainandbuildabetterworldonMars．Firstofall,transportshouldbemuchbetter．___________________________．However,by2100,spaceshipcantravelathalfthespeedoflight．ItmighttakeustwoorthreedaystogettoMars!Secondly,humansneedfood,waterandairtolive．ScientistsshouldbeabletodevelopplantsthatcanbegrownonMars．Theseplantswillproducethefoodandairthatweneed．However,cantheseplantsproducewaterforus?Thereisnoanswernow.ThereisaproblemforustoliveonMars．Marssuck（吸力）us...
