You’d better not smoke here, ________?
This is the best way I have thought of __________ the problem.
The part China __________ in the world now __________ by many countries.
There was a time __________ the people in my village lived a peaceful life, enjoying the beauty of nature.
I’m amazed to get in touch with my deskmate of Junior Middle school again. __________, it is ten years since we met last.
The chairman thought __________ necessary to invite Dr. Smith to speak at the meeting.