Do you know the stages every inventor must ________ before they can have their invention________ .
Theory is based on practice and ________ serves practice.
— How many of them do you want to act in the play? —_______ , and still a large number needed!
Since no other way to escape from the flood, ____ only safe thing is to take ____chance.
—Would you mind my using your bicycle for a while? — _________, but do return before 11.
The boy the teachers considered _____failed in the exam , _____surprised them very much .