The best way to explore _______ countryside is on _______foot.
The __________ on his face told me that he was angry.
The palace caught fire three times in the last century, and little of the original building__________ now.
Although medical science __________ control over several dangerous diseases, what worries us is that some of them are returning.
The meeting was concerned __________ reforms and every-one present was concerned __________ their own interests.
Rather than __________ on a crowded bus, he always prefers __________ a bicycle.