问题
选择题
“I know she was in because I heard her radio, but she didn’t open the door.” “She___the bell.”
A．may not be hearing
B．may not have heard
C．must not have heard
D．must not be hearing
答案
答案：B
考查情态动词。根据语境可知为对过去事情的推测，故用情态动词+ have done。may have done过去也许做过某事。根据句意为：她也许没有听到铃声。故选B。