The house, ______ door often stays open until late at night, works as a home for the guards, some of ______ are from the countryside.
__________ he is old, the old man still insists on studying at a night school.
__________! Let’s go there and have a look at it.
My father bought me _____ mp3, but I lost _____ mp3 yesterday.
_______the room,I found my cat lying on the floor,dying.
The noise _______ by the machine could be heard at night.