问题描述：
it's shame ___________able to give them any advice.
A. not to have been B.to have not been C.to have been not D.to not have been
应该选什么,为什么呢~~
A. not to have been B.to have not been C.to have been not D.to not have been
应该选什么,为什么呢~~
问题解答：
我来补答展开全文阅读