b I think you should talk to your teacher about it.
c You needn't be here before 8.00.
d Sam should know the answer.
e I had to go to the doctor's
f Cathy must be at the library
g What do you think I should do?
b) I think you should talk to your teacher about it.
c) You don't need to be here before 8.00.
d) Sam should know the answer.
e) I had to go to the doctor's
f) Cathy must be at the library
g) What do you think I should do?