The problem won't be settled until we____a chance to discuss it thoroughly.
问题描述：
The problem won't be settled until we____a chance to discuss it thoroughly.
A.Have had B.Have
为什么是a不是b?
答
have done表示完成,这句话：这个问题不能被解决决直到我们有机会把他详细的讨论一下
.
有机会去解决问题才可能把问题解决.解决问题发生在能不能得到一个机会之后.