He mended the mechanism, ___ (同时), she watched him.
The young couple are always ______(争辩) with each other about money.
We should care for the young and ______(尊敬) the elderly.
The police ______(观察) a man in black entering the bank.
It costs me a lot to travel around the world, but it was really ______(值得的), for it broadened my views.
I hope my kids will _______(表现好) themselves while I am away.