A red sky in the morning ________ to be a sign of bad weather.
_______ you don’t have much experience in this field, why don’t you ask ProfessorWang for advice?
—Shall we have a smoke here?—No, we _____ because this is gas station and the worker is carrying some petrol.
—Linda, I have to stay at school and take some courses next month, how about you?—I ____ to Canada at this time next month since I have got the visa.
—What do you think of teaching?—I find it fun and demanding. It is a job____ you are doing something seriousbut interesting.
—Our teachers and parents always warn us not to smoke.—Yes, actually, the risk of heart disease is a powerful argument ____ smoking.