问题补充:
(·吉林四校高三一诊)I really don know how to thank you, but for your help, I my lost necklace.
A. couldn have found
B. mustn have found
C. couldn find
D. wouldn find
答案:
(答案→)A. couldn have found
B. mustn have found
C. couldn find
D. wouldn find
解析:A句意:我真的不知道该怎样感谢你,没有你的帮助,我不可能找到我丢失的项链。couldn have done表示对过去情况的否定推测,意为“不可能”。