Question

【题目】Not until they left school________ how much their teachers loved them and helped them.

A．they realized

B．did they realize

C．they would realize

D．had they realized

Answer 1

【答案】B

【解析】not until后接状语从句位于句首时，主句要采用不完全倒装结构，所以A、C不对；又因为主句的动作发生在until引导的从句的动作之后，所以D项错误。