When he saw a wallet on the playground , he at once . A. picked it up B. gave it up. C. picked up it.
---Could you tell me when Mr. Li _______ in Changchun? ---Sure. When he _______, I’ll call you.
Kids _________ use the computers to draw in the future.
---Will there be more people in 100 years? --- __________, I hope.
Tom _______ his English book in the classroom last Friday.
I really don’t know____________.