What do you mean by that?
Do you mean only the boys have to take midterms?
Could you say that again, please?
Could you repeat yourself, please?
Could you clarify that, please? Would you elaborate on that, please?
Could you be more explicit?
Could you explain what you mean when you said I should submit my work by email?
Can you tell us a little more?
Could you give us an example? I wonder if you could say that in a different way.
Could you put it differently, please?
Could you be more specific, please?