核心问题
If you ____ Jerry Brown until recently, you'd think the photograph on the right was strange. A. shouldn't contact B. didn't contact C. weren't to contact D. hadn't contacted(全国研考,93-21)
此题答案为 D(hadn't contacted)。但这是不符合主句和从句的时态配合的呀！语法书上明确指出 if 从句为过去完成时，主句应当使用 would + have done。此外，上题为什么不能选 C(weren't to contact)?
词典解答
选 D 后,上面的句子叫做错综时间条件句,更详细的情形,请见 conditional sentences of mixed time 。上面的句子之所以不能选 C,是因为从句中有时间状语 until recently(直到不久前),它是与表示将来时间的 weren't to 相矛盾的。