题目

题型：难度：来源：

【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

答案

【答案】B

解析

【解析】
试题分析：句意：下课后，学生们应该把黑板上的粉笔字擦下来。A. was excepted to例外；B. are supposed to应该；C. are important to对……重要；D. was polite to对……有礼貌。结合句意，故选B
考点：考查短语辨析。