I suppose they must be trying out new ideas in the lab,__________.A.don`t I B.mustn`t theyI suppose they must be trying out new ideas in the lab,__________.A.don`t I \x05\x05B.mustn`t they C.aren`t they \x05D.needn`t they为什么选D呢?求详解
问题描述：
I suppose they must be trying out new ideas in the lab,__________.A.don`t I B.mustn`t they
I suppose they must be trying out new ideas in the lab,__________.
A.don`t I \x05\x05B.mustn`t they C.aren`t they \x05D.needn`t they
为什么选D呢?求详解
答