问题:
【题文】After class, students ______ clean the chalk off the blackboard.
A.was excepted to
B.are supposed to
C.are important to
D.was polite to
【题文】After class, students ______ clean the chalk off the blackboard.
A.was excepted to | B.are supposed to |
C.are important to | D.was polite to |
参考答案: