–A boy was killed by the tiger in the zo
题型：选择题
问题：
–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
–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