His supposition is good in theory _____ cannot be put into practice.A.andB.orC.butD.while

问题描述:

His supposition is good in theory _____ cannot be put into practice.
A.and
B.or
C.but
D.while

C

很明显 前后是转折关系 要用but

选C,
解析:根据意思,“他的猜想从理论上来说是很不错的,但是很难放到实践中去”故用but,不用别的.

C 解析:这里是转折的意思