21. Move a few steps, and the oil-paintings look better ______.
It was midnight _____we reached the station.
When he turned professional at the age of 11, Mike _____ to become a world champion by his coach and parents.
In some countries where there is not enough coal, water is used to ____ electricity.
How I regretted ______ the hours in the forest ______ I should have studied hard in the classroom.
All of the students were ______ by the ______ speech given by the headmaster.