Leonardo da Vinci birds kept in cages in order to have the pleasure of setting them free.

问题补充：

Leonardo da Vinci birds kept in cages in order to have the pleasure of setting them free.

A. is said to be buying

B. is said to have bought

C. had said to buy

D. has said to have bought

答案：

A. is said to be buying

B. is said to have bought

C. had said to buy

(答案→)D. has said to have bought

解析：be said to do sth. 意为“据说做某事”。本题中的buy动作发生在say动作以前，故用不定式的完成式。全句意为：据说达·芬奇曾花钱买笼鸟，以便享受放飞它们的快乐。