—— I haven’t seen Johnson these days.
—— I think she a conference in Beijing, but I’m not sure.
A. should be attending
B. might be attending
C. could have attended
D. must have attended
网友回答
(答案→)A. should be attending
B. might be attending
C. could have attended
D. must have attended
解析：本题考查情态动词。句中should表示“应当”之意。句意：——这些天我没有看到Johnson。——我想她一定在北京从句会议，但我不确定。