请教英语高手一道高中英语选择题~

题目

请教英语高手一道高中英语选择题~
Almost 80% of those _____ said that they were againest the steps taken by the government last week.
A.survey B.surveying C.surveyed D.who surveyed
答案是C,为什么不选D?详解一下吧~
谢谢!
考察的什么知识点？

答案

对,他们说的对,这是考察的：1.被动语态,这些人是被调查,所以A,B不对2.定语从句的省略,完整的句子是Almost 80% of those (who were surveyed )said that they were againest the steps (which were taken by the gove...