Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
_____ on the stairs than the phone rang.
A. No sooner had I stepped
B. Had no sooner I stepped
C. No sooner I had stepped
D. Had I no sooner stepped
Đáp án là A
Đảo ngữ: No sooner+ had+ S+ PP than + S+V_ed: ngay khi… thì…