Question

AIDS ls said ________ the number-one killer over the past few years in this area．

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

Answer 1

C
本题考查sb．/sth．is said to be/do/have done这一固定结构，根据后面的over the past few years而选取完成形式。