--Why are you smoking so much these days?--Sorry. I just can't help .
—Could you tell me ___________? —About three hours.
He will send me an e-mail as soon as he _____ in America.
In the street I met the professor______ gave us a talk last week.
Paul doesn’t have to be made _______ . He always works hard.
—Would your brother go for a picnic this Sunday? —If I don’t go, _______________.