1 . I will no longer use one-off things and________ (取代) plastic bags with paper bags. （根据汉语提示单词拼写）

2 . —Where did you get this book?
—I picked it up from a second-hand bookshop if you ______ know.

A．must

B．will

C．can

D．shall

3 . — Don’t forget to watch the game and cheer for our team tomorrow.
—OK, I ______.

A．mustn’t

B．wouldn’t

C．won’t

D．don’t