Cook was a strict but good captain, _________ who, usually, took care of the sailors on his  ship.

— Come on! Let’s go to the net bar.— What? _____ you ever want to do is going online. 

It is no use fishing for golden fish in this river; there are _____ left. 

The two runners are neck and neck; _______ of them could win the race.

—Can I come this afternoon or tomorrow morning?—         is OK. I'm free today and tomorrow.