问题
选择题
“Not having returned home yet, _________”, his father said to the police.
A．his mother got worried
B．his mother must be worried
C．I think he is missing
D．he must have got into some trouble.
答案
答案：D
句意：他的父亲对警察说：“还没回到家呢，他一定陷入了困境当中。must have done表示对过去事情肯定的推测。所以选D。