－Tom, who taught          Chinese before you came to China?－Nobody. I learned it by        .

—What do you think of the two backpacks? —______ of them are very nice.

—Have you brought        with you? We won’t have time to come back.—Don’t worry. All the things we need are here, in this big bag.

There are many flowers and trees on ______sides of the Century Road.

—______is your birthday gift, Linda? — It’s a circle.