【题目】AIDS is said _______the biggest health challenge to both men and women in that area in the past three years.
A.that it is.B.to be.
C.that it has been.D.to have been.
在线课程【答案】D
【解析】
考查非谓语动词。句意：在过去的三年中，艾滋病被认为是该地区男性和女性面临的最大的健康挑战。题干中考查句式“sb./sth. be said+动词不定式”，且事件已经发生，故用不定式的完成式，故选D。