—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：考查情态动词。根据It's class time可知，对苏珊在哪里比较确定，选D意为，他现在应当在教室，表示合乎理想的情况，B,C是对过去的推测，不符合题意，A表示可能。