Question

AIDS is said ______ the biggest health challenge to both men and women in that area over the past few years.

1. A.
   that it is
2. B.
   to be
3. C.
   that it has been
4. D.
   to have been

Answer 1

D
解析：
句意：據(jù)說，在過去的幾年中，艾滋病對于那個地區(qū)的男女來說已是最大的挑戰(zhàn)。It is said that從句可轉(zhuǎn)為sb./sth. be said to do/to be doing/to have done的形式。由此可淘汰A、C兩項，由于句子中的時間狀語over the past few years要用完成時，所以淘汰B項選出正確答案D。