II. 单项选择（共10小题；每小题1分，满分10分）
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
11.My younger cousin is now on ______ diet. She is trying to lose ________weight.
A. /; / B. a ; / C. the; a D. the; the
12.--- Must I go there right now?
--- No, you_________.
A. don’t need B. mustn’t C. don’t have to D. hadn’t better
