---- You _____ have given them some advice.---- So I did, but who cared what I said?
— What about the price of petrol now? — It has been ______ 20 percent since the beginning of this year.
The old man was taking a walk, ____ by his grandson.
An expert was _____ to give a speech on how to learn English well.
Scientists have made a major ____ in cancer research.
His success _______ his hard work.