---- Who(谁) are they?---- __________.
They will call us as soon as they ______ there.
— Were you at home at that time?— No, I ______ dinner with my friends in a restaurant.
— Which do you think is ______ subject, math, music or art?— Art, I guess.
Mike invited me ______ tennis this weekend.
— What about this dress? — I don’t like the colour. Please show me ______ one.