One hundred percent _______ to your studies, though it can be lonely and no fun at all, will leave precious marks on your youth.
It was when she was about to go to bed ______ the telephone rang.
None knows if _______ that boy, but if _______ him, her parents will be disappointed.
The problem is _____ has caused us a lot of trouble.
He pointed to ______ looked like a tomb and said, “Ghost.”
. We are living in an age ______ many things are done on computer.