问题
选择题
Only after they had discussed the matter for a few hours ______ a decision.
A．they reached
B．did they reach
C．they reach
D．do they reach
答案
答案：B
题目分析：考查倒装。Only+时间状语或从句，放句首时，主句用部分倒装，A、C没倒装，排除A、C；根据had discussed可知，空白处使用过去时，排除D。故选B。