So difficult_____it to acquire a large vocabulary without the help of a teacher that he was close to giving up .
Mr Black must be worried about something. You can ____ it from the look on his face.
____ has recently been done to provide more buses for the people, a shortage of public vehicles remains a serious problem.
I have no dreams ____ to have a happy life.
This problem may lead to more serious ones if ____ unsolved.
I ____ you, but I didn’t think you would listen to me.