1)must
2)may
3)can | must
4) can
8) if you
10)may
2.
this medicine I have to take 3 times a day
you can get a doctor's appointment at 11 o'clock
if your classmate is sick with the flu he needs to stay in bed for a few days
can't eat much ice cream. You have a sore throat
извини, больше не могу