问题补充:
--- Hi, Lucy.Do you know where Linda is?
--- She in the library.I saw her there just a few minutes ago.
A. shall be
B. must be
C. should have been
D. might have been
答案:
A. shall be
(答案→)B. must be
C. should have been
D. might have been
解析:考查情态动词must表推测的用法。must + do表示对现在事情的推测。所以选B。