问题
选择题
In the lecture, little Tom kept silent all the time unless _________ to express his opinion.
A．he invited
B．he is invited
C．invited
D．being invited
答案
答案：C
题目分析：句意：在演讲中，小汤姆一直保持沉默，除非他被邀请发表自己的看法。动作invite与其逻辑主语little Tom之间是被动关系，故用过去分词作状语，可知选C。