Our school has about 100 computers, but only sixty percent ____ used regularly.
He has been fired and will have to________over charge of his office tomorrow.
In his speech the headmaster________to the great help the school received from the district government.
John was so________that he could hardly keep his eyes________.
He kept the light in his room________the whole night.
________you put your heart into your study, you'll feel________in it.