【简答题】_______ the people have become s of their country _______ science can really serve the people. A.It is only then; that B.It was that; when C.It is only when; that D.It was when; then
【简答题】许多的动物可以在陆地上交配,而蝴蝶只能在______交配。
【单选题】_____ the people have become masters of their country _____ science can really serve the people. [ ]
【多选题】生态系统中能量的流动,是借助于()来实现的。
【多选题】生态系统中能量的流动,是借助于( )来实现的。
【简答题】生态系统中能量的流动是借助于 和 来实现的。食物链和食物网便是生态系统中能量流动的渠道。