19.Obligation and Necessity.
I must tell you the truth.
Must you go now?
He must go now,it's getting late.
The bus is coming.I've got to go.
You should tell me earyly about that.
We need to buy some gifts for her birthday.
I am supposed to attend the meet in Beijing next month.
You are supposed to finish the homework before going home.
It's necessary to go over the lesson right now.
Is it necessary to go to the hospital to see the doctor?
Ought I to see the doctork,do you think?
Must we dress up for her birthday party?
Do I have to go before next Wednesday?
You have to make a dialogue about the situations before we finish the class.
We don't have to give it to him?
Should we speak in English at the meeting?
You needn't go out to work after the first baby.
There is no need for them to change the time.
He should have come.
A:Do I have to watch my hands before supper?
A:Then,do I need to use the soap?
B:No,you needn't.Just use the clean water.
A:Mum,do I need to go to see the doctor?
B:No,I don't think so.But you must stay at home hor a day or two.
B:Yes,I am afraid you must.
A:Should we tell the teacher about that?
B:Yes,of course.You ought to tell him as soon as possible.