问题补充：
Which of the following is NOT right?
A. It was not until I reached London that I realized that my English was so poor.
B. Not until I reached London did I realize that my English was so poor.
C. I didn’t realize that my English was so poor until I reached London.
D. It was not until I reached London that did I realize that my English was so poor.
答案：
A. It was not until I reached London that I realized that my English was so poor.
B. Not until I reached London did I realize that my English was so poor.
C. I didn’t realize that my English was so poor until I reached London.
(答案→)D. It was not until I reached London that did I realize that my English was so poor.
解析：考查强调句型和倒装句。当否定词放在句首的时候，后面的主句要使用部分倒装的形式。B项正确。C项是正常语序的not…until…用法；A项是正常语序的强调句型。在强调句型中也要使用陈述语序。故D项错误。
