Question

I enjoy the party very much, but I_______ go home. It's too dark.

1. A.
   leave to
2. B.
   may
3. C.
   mustn't
4. D.
   can't

Answer 1

A
点拨：本题考查情态动词must及have to的用法辨析，通读全句可知“必须”回家的原因是“It's too dark”，是客观因素，而不是发自内心的，即“have to”。