.The wallet _______ several days ago was found _______ in the dustbin outside the building.
“Is there _____ here?” “No, Bob and Tim have asked for leave.”
I'll come to see you if _____.
—Must I turn off the gas after cooking ? —Of course . You can never be _______ careful withthat.
_____ is known to everybody, the moon travels round the earth once every month.
It is so difficult a problem that _____ student in this class _____ work it out.