—Hi, Johnson, any idea where Susan is?
—It’s class time, so she in the classroom now.
A. can be
B. must have been
C. might have been
D. should be
网友回答
A. can be
B. must have been
C. might have been
(答案→)D. should be
解析：
这题考查情态动词的用法，should在这儿表示“主观推测、应该”，句意是：Johnson知道Susan在哪里吗？---现在是上课时间，她应该在教室里。