Aids is said_____ the biggest health challenge to both men and women over the past few years.

题目

Aids is said_____ the biggest health challenge to both men and women over the past few years.
A.that it is B.to be
C.that it has been D.to have been
选C还是选D啊?时间又是过去..选D

答案

It is said that..或者 主语+ is said to be...这是常用的固定句型,由此,A、C语法上时错误的.再看时间,“over the past few years”,明显是过去已经完成的了,所以选D.
楼上的看清楚,主语是“Aids”,而不是形式主语It...C是错误的