---Why do you keep the windows open on such a cold day? ---There are so many students here, so we want to keep the air nice and __.

–Peter, __________ do you visit your grandparents?    --Twice a month.

—Jim, have you done  homework_________?---- Yes, I have _____ done it.

Now the air in our hometown is ___________ than it was before. Something must be done.

You are a little___. I’m afraid you should do sports every day.