Manypeopledreamoftravelingintoouterspace.However,spend...
问题详情: Manypeopledreamoftravelingintoouterspace.However,spendingtoomuchtimeinspacemaycausehealthproblems,accordingtoNASA.That'swhyastronautsshouldn'tspendmorethansixmonthsontheInternationalSpaceStati...