The law of over－learning explains why cramming (突击学习) for an examination, though it may result in a passing grade, is not a ________ way to learn a school course.[ ]

My father has decided to ________ smoking.—That’s good news for us.

It was playing computer games _____ cost the boy plenty of time _______ he ought to have spent doing his lessons.

Once a neighbour accused me ________ playing my radio too loudly —Oh, you had the right to defend yourself ______ the charge

How brave he was! His fame ______ all theother parts of the country soon.