It was not until __ that __ to prepare his lessons.

问题描述:

It was not until __ that __ to prepare his lessons.
a.did his father come in ;the boy began
b.his fanther came in;the boy began
c.did his father come in ;did the boy begin
d.his father came in ;did the boy begin
为什么?

首先这是一个It be that引导的强调句,然后又涉及到not until句型及其倒装.正确语序是:The boy didn't begin to prepare his lessons until his father came in.not until 倒装句中,主句倒装,从句不变.