Some people prefer to work and live in Chengdu, for the price of an apartment is less than half of ________ of big cities like Beijing, Shanghai, and Guangzhou.
Only when you have finished your homework ______ go home.
It was in the street ______ I live that I met Mr. Green.
Was it in this hospital _______ she lived for ten years ______ she was trained to be a real nurse.
It was only when the war broke out ______ he began to realize everything was too late.
It was ten years ago ______ we last met in our hometown.