He ________ to swim when he was five.

— I am going to spend my holiday in the countryside. — ________. The air there is fresh and the views are attractive as well.

 Whose  book  is that ?It   _______belong to Linda .Look !Her name is on it .

—The research on the new flu virus vaccine is challenging and demanding. Who do you think can do the job?     —______ my students have a try?

The bicycle looks much like mine, but it isn’t.        it be John’s?