题目

It was not until midnight      they reached the camp site. A. that            B. when C. while           D. as 答案：A 解析: 本题考查not until的强调句型。It is /was  not until …… that ……小明和小华比赛爬楼梯，小明的速度是小华的两倍，当小明爬到第7楼时，小华爬到了44楼．