13. — How do you keep fit?— By having a healthy diet and _________ regularly.
—Did you enjoy staying with your friend last week, Lily?—Yes. I _______ with him for a long time.
—What’s the matter with Della?—Well, her parents wouldn’t allow her to go to the party but she still _______.
, the sun was rising in the east.
Across North China in the world, namely the Great Wall.
—Pity you missed the lecture on nuclear pollution.—I _______ it ,but I was busy preparing for a job interview.