She _________ watching TV, but she ____________ listening o the radio.

Mrs Chen ________ the shopping centre for an hour. She is buying a dress now.

Have you finished your homework ________? –Not ________. I was playing computer games.

At last our head teacher ______ who broke the window of the classroom.

Look at the boy running on the ground. Is it David?– It _______ be him. I saw him go to the teacher’s office just now.