---Look at the boy running on the playground. Is it David? ---It ______ be him. I saw him go to the teachers’ office just now.
You are working too hard. You’d better keep a__________ between work and relaxation.
Some people won’t realize the value of their health ________they lose it.
Jackie Chan played the lead role ______an excellent policeman _____the film.
This programme is a___________ TV show, so you can send text messages directly to the station to vote for your favourite singer.
It’s quite warm here, we_________ leave the stove on .