1. --- you come with me to Lang Lang's piano concert this evening?
--- I'd love to, but I have to study for my math test.
A. Should B. May C. Must D. Can
2. --- you come to my birthday party tomorrow, Robert?
--- I'm afraid not. I have lots of homework to do.
A. Must B. Should C. Can D. Need
3. --- you come here next Friday?
--- Sorry, I can't. I have to study for a test.
A. Need B. Must C. Can D. Should
