Ngữ Pháp và Từ Vựng Not until ......................... A. I approach...

Ngữ Pháp và Từ Vựng

Not until .........................

A. I approached the flat that I realized that it was completely empty.
B. did I approach the flat that I realized that it was completely empty.
C. I approached the flat did I realize that it was completely empty.
D. did I approach the flat I realized that it was completely empty.