问题描述：
为什么 —----------?—Should we spend billions of dollars dollars on space research?
A.How are you today?B.How about you?
C.Do you agree then?D.Why have they done that?
A.How are you today?B.How about you?
C.Do you agree then?D.Why have they done that?
问题解答：
我来补答展开全文阅读