—Don’t _____ so often. It’s bad for your health.—I have to. But I know I should have enough sleep.
We are sure one day the air in Beijing will be much ______ than today.
What a nice day! We decide ______ out for a picnic.
— Have ______ cup of coffee, please. — Thank you.
John ______ leave for New York tomorrow, but I’m not sure.
Be careful with the knife, ______ you’ll be hurt.