三、考查not...until...句式的强调句形式
not...until用于强调句时的基本形式为“It is (was) not until...that...”。如：
1. It ______ we had stayed together for a couple of weeks ______ I found we had a lot in common. (浙江卷)
A. was until; when B. was until; that
C. wasn't until; when D. wasn't until; that
【解析】答案选D。此题考查not...until...句式的强调形式。又如：It was not until she took off her dark glasses that I realized she was a famous film star. 直到她取下墨镜，我才意识到她是一位著名影星。
2. It was not until she got home _______ Jennifer realized she had lost her keys. (全国III)
A. when B. that C. where D. before
【解析】答案选B。考查not...until...句式的强调形式。又如：It was not until I met you that I knew real happiness. 直到我遇到你以后，我才真正体会到幸福。

四、考查强调句与非强调句的辨别
1. It will soon be five years ______ we came to live in Cairo.
A. that B. when C. since D. as
【解析】答案选C。此题不是考查强调句，而是考查since的用法，句意为“我们来到开罗居住快五年了”。又如：It is two years since he left the country. 他离开这个国家已经两年了。/ It's quite some time since we wrote to each other. 我们互相通信已有不少时间了。
2."Was it here _____ you were away talking to a friend?" "Sure. But when I got back there, it was gone."
A. that B. while C. which D. where
【解析】答案选B。此题不是考查强调句，而是考查while的用法，while在此表示“在……期间”，句意为：当你离开去跟朋友说话的时候它在这儿吗？