A:生产关系一定要适合生产力状况
B:上层建筑一定要适合经济基础状况
C:生产力一定要适合生产关系状况
D:经济基础一定要适合上层建筑状况
下列对某未知溶液中离子的检验方法及其结论一定正确的是( )
A. I spent two hours there.
B. He is Yang Liwei.
C. I went to my friend's house.
D. I was born in 2004.
E. No, I didn't.
国外旅游,严禁从国外带水果等农产品,其原因是( )