If I had been a little more careful, I the wallet behind.
A. won't leave
B. hadn't left
C. didn't leave
D. wouldn't have left
网友回答
A. won't leave
B. hadn't left
C. didn't leave
(答案→)D. wouldn't have left
解析：句意：如果我能小心一些，我就不会丢下钱包了。If条件句用了had done，说明是和过去相反的虚拟语气，主句用would have done表示对过去情况的虚拟，所以选D。