When solving the problem a second time, you’d better be more careful____you made a mistake.
The museum he paid a visit _____ at the end of the street.
The day will come _____ the people all over the world will get rid of poverty.
He is over sixty, but doesn’t look _____.
Why is it _____ he can’t get along well with his classmates?
Mary wrote an article on _____ the team had failed to win the game.