not until 有三种用法结构,除了最基本的大家都会的基本结构,还有的就是强调结构和倒装结构
这道题考的就是强调B与倒装A
A选项是倒装即It was not until yesterday did Janet tell me the truth.
什么时候选B——中间加that构成it was not until + 从句+that+ 主句,即
It was not until yesterday that Janet told me the truth.