Mywalletisnowheretobefound.I_____itwhenIwasonthebus.
D
must have+done 用于推断过去某个时间肯定发生了的事情。
Hisarticleisbetterthan_____intheclass.
Icanspeak_____German.
Itseemsasifthesun_____roundtheearthsinceitrisesintheeastandsetsinthewest.
Thosepeople_____ageneralunderstandingofthepresentsituation.
Hedrovefastandarrivedanhour_____ofschedule.