-----Who has made a mess in my room? -----Who else         it but your naughty son?

----Will you take up teaching as a career after graduation?---- Hard to say. I ________ go abroad for higher education instead, but it depends. 

— I think the man over there must be Bob.— It _______ be him. He has gone to England.

—May I         this pair of blue jeans? —Yes, you        .

 ----You needn’t take an umbrella. It isn’t going to rain.----Well, I don’t know. It_____do.