I.单项选择（共15小题；每小题1.5分，共15分）
1. —Could I borrow your dictionary?
—Yes, of course you_________
A. might B. will C. can D. should
2．—Shall I tell John about it?
—No, you ______ . I've told him already.
A. needn't B. wouldn't C. mustn't D. won’t
3．—Is Jack on duty today?
—It_____ be him. It’s his turn tomorrow.
A. mustn’t B. won’t C. can’t D. needn’t
