Question

If my sister hadn't thought it over and over before making the decision,she______ a mistake.

A.had made
B.made
C.would made
D.would have made
要详解啊～

Answer 1

D
本题考查虚拟语气。表示对过去的推测的句型是：
If + 主语+谓语（过去式），主语+would have done.

Answer 2

A 吧。前面是过去完成时，前后一致。我觉得应该是，不做英文很多年