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。
Hewasvery_____togo,buthehadnochoice.
He‘sworkinghard_____.
He drove fast and arrived an hour_____of schedule.
Beingextremely_____tothecold,Idonotlikeskating.
Yourbikeneeds_____.You‘dbetterdoirightnow.