It is _____ he often fails in exams _____ makes his parents worried about him.

______ can make my mother change her mind. She is sucha person who never gives up easily.

well known that knowledge is ____treasure house, but practice is ___ key to it.

I’m afraid the headmaster is _________ busy to meet the visitors

I still remember _______ the grand school usedto be a abandoned airport two years ago