问题
选择题
Hurry up! They ________ for us at the crossing.[ ]
A. must wait
B. must have waited
C. must be waiting
D. may wait
答案
答案:C
Hurry up! They ________ for us at the crossing.[ ]
A. must wait
B. must have waited
C. must be waiting
D. may wait
答案:C