Ex.1 Underline the correct answer

 

A: Good morning, madam. May/must I help you?

B: You might/mustn’t
be able to. I need a ball of wool that is the same color as my jumper.

A: Just a moment, please. I must/mustn’t look in the stock room. We might/might not have some left. I’m not sure.

B: The wool must/mustn’t
be exactly the same color, it must/mustn’t
be different.

A: Could/Mustn’t
I ask you a question, madam?

B: Yes.

A: What do you want the wool for?

B: I could/must
finish knitting this jumper. It only has one sleeve at the moment!