题目内容：
My wallet is nowhere to be found.I_____it when I was on the bus. (A) must drop
(B) should have dropped
(C) had dropped
(D) must have dropped
参考答案：
选择题：My wallet is nowhere to be found.I_____it when I w
- 题目分类：郑州工程技术学院-建筑CAD
- 题目类型：选择题
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(A) must drop
(B) should have dropped
(C) had dropped
(D) must have dropped