还得麻烦你了Ihopescientists_____(find)acureforcancer
Bythemiddleofthiscentury,morepeople_____(live)incitiesthaninthecountry
Tenyearsfromnow,people______(wear)smartclothes
Noone_______ever_______(live)onMars
Humans________(live)onanotherplantsfivebillionyearsfromnow
Achineseastronaut______(reach)Marsby2050