____ is known to all is ____ Diaoyu Island is part of China.

A reward of $1,000 will be given to      can provide any clues to the case which has been investigated by the police for nearly half a year.

How long do you think it was ______ he got home in such bad weather?

It was ______ his office.

______, Guo Mingyi makes his effort to help those in poverty.

As soon as he comes back, I’ll tell him when ___ and see him.

Have you seen Tom recently? I wonder ____ with his studies.

_______ puzzled Li Lei a lot was _______ his best friends didn’t come to school this morning．

Only when the war was over _______ return to his hometowns．

——Did you know any Chinese before you arrived in Beijing?
——Never ________it, actually.