If you make_ _ most of forty-five minutes classes day after day, there will be ______switch in grades.
Do you think the concert last weekend was of __________?
The girl asked, "Could you help me solve the math problem?" "Of course, I can." he replied __________.
It was __________ computer games that cost the boy a lot of time __________ he ought to have spent onhis lessons.
Only in this way __________ to make improvements.
In order to find __________ better job, he decided to study __________ second foreign language.