一Shall we go out for a trip to relax ourselves after the final exam?
All the class keep quiet _________ the class begins.
Many people go to Tian’anmen Square to watch the national _________ rise on National Day.
We will have a week _________ next month. We’re going to take a vacation.
My uncle bought me a book for my ___________birthday.
—Hurry up! The bus is coming. —Wait a minute. Don’t cross the street ____________the traffic lights are green.