有关高中英语The secretary worked late into the night,( )a long spe

问题描述：

有关高中英语
The secretary worked late into the night,( )a long speech for the president.
A.to prepare
B.preparing
C.prepared
D.was preparing
答案为B,为什么不把它当作原因状语从句选C?

1个回答分类：英语 2014-10-05