【题目】AIDS is said______ the biggest challenge to both men and women in the area over the past few years.
A. that it isB. to be
C. that is has beenD. to have been
在线课程【答案】D
【解析】
考查不定式的完成式。句意：据说艾滋病是过去几年来该地区男女面临的最大挑战。it is said to是固定结构，over the past few years表明此处表示的动作先于is said发生，应该用不定式的完成式，故D项正确。