To improve their oral English, everyone in the class is supposed to ______ actively in these discussions.

Mrs. Smith found the toys here and there, so she asked her son to ______ his toys before having dinner

It was three o’clock _______ he came back from work.

Could you please tell Lucy that I want to talk to her? —Sure, I will tell her as soon as she _______ back.

_____ does it take you to go by bus from Tianjin to Beijing? —About five hours.[ ]