—What will you do next Sunday?
—Maybe do some shopping, for I go to school on Sunday．
A. mustn’t
B. shouldn’t
C. don’t have to
D. had better not
网友回答
A. mustn’t
B. shouldn’t
(答案→)C. don’t have to
D. had better not
解析：考查情态动词。mustn’t 禁止，shouldn’t 不应该，don’t have to 没有必要，had better not 最好不，句意：下周日你干什么？也许买东西，因为在周日我不必去上学。所以选C。