--- Don’t forget _________ your homework, John. --- OK, I’ll do it right now.
----Look at the boy running on the playground. Is it David? ---- It ______ be him. I saw him go to the teachers’ office just now.
---With 4G mobile phones, people can even see each other as they talk. ----Really? Would you show me it, please?
--______ to Hong Kong?-- Yes, and I will be back next month.
They were _______ busy ______ the project ______ the time.
---- He’s never seen the film The Grand Master(一代宗师)before, _________he? ---- _____________. He went to see it last week.