After five years of preparation，Shanghai presented the world many said was the greatest Special Olympics.
A. when
B. what
C. where
D. which
网友回答
A. when
(答案→)B. what
C. where
D. which
解析：此题中，present接了双宾语，一个是the world，另一个是what引导的宾语从句。what引导的宾语从句又是一个主从复合句，said的宾语从句中缺少主语，因此只有what能引导从句。