_______ the boy beside the window?
—What is a writing brush, do you know? —It’s used ______ writing and drawing.
He used to ____in the sun, but now he is used to ____at night.
My father isn’t in good health now. I think he should pay attention____ exercise.
— Don’t worry. He’ll come and help you. —_______he doesn’t come?
I can play the guitar, _________ his brother.