–A boy was killed by the tiger in the zoo.
–He was believed into the cage while feeding the tiger without permission.
A. to fall
B. to be falling
C. to have fallen
D. having fallen
网友回答
A. to fall
B. to be falling
(答案→)C. to have fallen
D. having fallen
解析：这题考查句型;Sb、sth is believed to have done“某人，某物据相信已经做了”，句意是：--一个男孩在动物园被老虎吃了。--据说他是未经允许喂老虎时掉入笼子的。因为这件事已经发生，所以用不定式的完成式。选C。