A large flock of birds__Flight 1594,the captain had no choice but to land in the river.为什么必须填hitting做独立主格结构?填hit为什么不行?

A large flock of birds__Flight 1594,the captain had no choice but to land in the river.为什么必须填hitting做独立主格结构?填hit为什么不行?
A large flock of birds__Flight 1594,the captain had no choice but to land in the river.
为什么必须填hitting做独立主格结构?填hit为什么不行?

A large flock of birds__Flight 1594,the captain had no choice but to land in the river.为什么必须填hitting做独立主格结构?填hit为什么不行?
如果填 hit ,那么 A large flock of birds hit Flight 1594 就是个独立的句子,主谓宾俱全,后面应该用句号,或者后句前要加连词and.
用hittting,表示在这种状况下,前句作为状语从句,而不是一个独立的句子.