---Why is the classroom so dirty? --- Sorry, sir. It ______ yesterday. We forgot to do it.
We ______ four thousand new words by the end of last year.
— Did you meet Tom at the airport? — No. His plane ________ by the time I ________ there.
— What is your Chinese teacher like? —
— What about playing football this afternoon, Sam? — I would rather at home than football. It’s too hot outside.
After the discussion, the students asked their teacher next.