The air in the countryside is       , so many people from the city drive cars there on weekends.

It’s difficult to live in a foreign country, ______ if you can’t understand the language there.

I’m surprised that John is only 25. I thought he was ________ , for he seems to be in his thirties.

The children are making __________. How __________ they are playing!

The old man was _______ sad _______ say a word when he heard the bad news.