问题补充：
It was in the exam that how much time I had wasted.
A. not until I failed;I realized
B. until I failed; I didn’t realize
C. not until I failed; did I realize
D. until I failed; I realized
答案：
(答案→)A. not until I failed;I realized
B. until I failed; I didn’t realize
C. not until I failed; did I realize
D. until I failed; I realized
解析：考查强调句型。本题强调的是施加状语从句not until I failed in the exam，在强调句型中，后面的句子要使用陈述语序。句意：直到我在考试中又一次不及格了我才意识到自己浪费了多少的时间。故A正确。
