题目

题型：不详难度：来源：

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

A．mark

B．chance

C．signal

D．measure

答案

C

解析

词义辨析。mark 标志，符号；chance  机会，运气；signal  信号，暗号；measure测量；尺寸。句意：在我们班的，当铃声响时，老师合上他的书，这对于每个人来说是一个起立的信号。故选C。