单项选择题
People wandering in the fairground or park area（）wear a uniform.
A.must B.mustn‘t C.have to D.don‘t have to
单项选择题 Not until most of the people had left the airport（）his sister was there.
单项选择题 Not always（）they want (to)
单项选择题 --We want to sit at the table near the window. -- I‘m sorry, but（）already.
