Question

In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.

A. signal        B. chance          C. mark            D. measure

Answer 1

A.

解析:

根据句意可知打铃及老师合上书本，这是下课的暗示，选项中只能选择signal。chance“机会”，mark“分数，痕迹”，measure“方法，措施”。