Not until he left his home ________ to know how important the family was for him.
He is disappointed. He appears ____ what has happened to his competition.
I was watching the news on TV ________ the power went off.
It was not until I failed in the test ______ I realized I had wasted too much time instead of preparing for it fully.
As is widely acknowledged, a great number of traffic accidents ____ numerous deaths and countless property loss all over the world very year.
Mr. Lee suggested that all of us go out to have a walk to refresh our mind ________ classes.