俗话说“一母生九子,连母十个样”,体现了生物多样性的哪个层次( )
A:基因的多样性
B:形态结构的多样性
C:种类的多样性
D:生态系统的多样性
“早穿棉袄,午披纱”反映的是( )
I thought you would come on time yesterday, but you left me ____ (wait) for nearly half an hour.