They waited silently （）．A．for the film beginBwhen thefilm began为什么选B?

Question

They waited silently （）．A．for the film beginBwhen thefilm began
为什么选B?

Answer 1

如果选A,要改为：
A．for the film 【to】begin
wait for sb to do sth 结构
如：
They are waiting for the library to open.
They are waiting for the bus to come.
所以只能选B,when the film began 是时间状语从句,修饰waited 这个谓语