—_________ I borrow your history book?—Sure. Here you are.

——Can I walk across the road now, mum?——No, you_______. You have to wait until the light turns green.

—When I first got to Harvard, my awkward English brought me great trouble.——Oh, dear, it _______a struggle for you to keep up with other students.

－__________ can you finish your homework, Ben?－ In thirty minutes. 

A: ________ I go to the airport to see Uncle David off tomorrow morning, mum? B: No, you needn’t. You may join us if you want to.