— Show me your permit, please.
—Oh, it's not in my pocket. It_______________.
A. might fall out B. could fall out
C. should have fallen out D. must have fallen out
— Show me your permit, please.
—Oh, it's not in my pocket. It_______________.
A. might fall out B. could fall out
C. should have fallen out D. must have fallen out
D
本题答句中fall out的动作发生于过去，英语中情态动词后加动词的完成式表示对过去动作的猜测，故选D。C项意为“本来应该掉出来”，不合题意。