Can
on
I'd
you
can't
have
Can
may
I'll
Sorry,I can’t.I have to prepare for my math test.
Sorry,I can’t.I must visit my grandparents.
Sorry,I’m afraid I can’t.I will go to the concert with my parents.
Sorry,I’m afraid I can’t.I will go to the summer camp.
Sorry,I’m afraid I can’t.I have to go home early to look after my little brother.
(本大题答案仅供参考）