3. You must do it right now.
5. You should do it first.
7. Is there any need for us to get a visa?
9. I don’t really think you want to.
M2: And must I go back to school?
M2: What else I’ve got to do? Join the army?
M: No, you don’t have to. But I think you ought to.
W: Oh, well. If I must, I must.
M: But this is how I like them, Mum. They’re just beginning to look right.
M: How’re you today?
M: What’s the main idea in this essay?
W: What’re you doing now?
M: I’m watching TV.
M: I will.
W: And don’t ever forget it.
W: You’re right.
M: Look! The iron is still on.
W: I should have turned it off. I’ll turn it off now.
M: Look at my nice blue shirt, there’s a big hole in it.
W: I’m sorry, Jim.
M: Never mind, dear.
I have some obligations today. I should copy these sentences, add this figures, but I don’t feel like it. Then my mother comes back. She complains she also has some obligations. She ought to tidy the room, dust the furniture, polish the floor and cook meal. My father is no exception either. He’s supposed to wash the car, repair the fence and post these letters. What a busy day!