The test not only helps make our _____ acquired knowledge permanent, but also enables us to find out what needs to take more time to improve.
_________ is known to all that he can't answer the question __________ he found the money.
I would gladly pay __________ for the book, because it is quite a use- ful one.
__________ with the size of the whole earth, the highest mountain does not seem high at all.
The number of people who __________ killed in the earthquake __________ reached 30,000.
He still does not get the point. How many times do I have to repeat myself to get it __________?