He hasn’t slept at all for three days. _______ he is tired out.
Americans eat _______ vegetables each person today as they did 20 years ago..
— Would you allow me ________ here? — Sorry. We don’t permit _________ in the lab.
— Do you know where David is? I couldn’t find him anywhere. — Well. He ________ have gone far — his coat is still here.
Sara hopes to become a friend of _________ shares her interests.
He has some doubt ________ he will succeed in his research work.