Spaceisadangerousplace,notonlybecauseofmeteors(流星)butal...
问题详情：Spaceisadangerousplace,notonlybecauseofmeteors(流星)butalsobecauseofraysfromthesunandotherstars.Theatmosphereagainactsasourprotectiveblanketonearth.Lightgetsthrough,andthisisnecessaryforplants...