问题补充：
Not until we have had a chance to discuss it thoroughly perfectly.
A. the problem has been settled
B. has the problem been settled
C. will the problem be settled
D. the problem was settled
答案：
A. the problem has been settled
B. has the problem been settled
(答案→)C. will the problem be settled
D. the problem was settled
解析：C
解析句意为：直到我们有机会充分讨论这个问题，它才能被圆满解决。not until置于句首，主句用部分倒装，助动词置于主语前；由until引导的时间状语从句用的是现在完成时(表即将完成的动作)可知，主句用一般将来时。
