---Where did you find our chemistry teacher? ---It was in the lab he was doing his experiment.
September 30 is the day ______ which you must pay your bill.
. ----I’d like some more beer. ----Sorry, there’s ______ left.
I cannot get my son to understand that extra time _______ now will pay off in the future.
____, Mother will wait for him to have dinner together.
I know nothing about the young lady ____ she is from Beijing.