有学者说：“中国古代的早期国家夏商周三代是一种部族国家。”这主要是因为这些国家[

That store is _      sale. They sell clothes     _very good prices.

A．on, at

B．at, in

C．of, under

D．for,to

Were it not for the snowy weather, we ________ all right.

A．would be　　

B．would have been

C．were

D．may be

眼部外伤后可能出现哪些病变？

奥尔夫体系的教学组织形式是（）和综合教学。

A.小组教学

B.个别教学

C.集体教学

D.混合教学

焦虑性失眠与抑郁性失眠在失眠的主要特点上有何区别？