We are sure one day the air in Beijing will be much ______ than today.
A. clean B. cleaner
C. cleanest D. the cleanest
What a nice day! We decide ______ out for a picnic.
A. go B. going C. went D. to go
— Have ______ cup of coffee, please.
— Thank you.
A. others B. other
C. another D. the other
John ______ leave for New York tomorrow, but I’m not sure.
A. must B. may
C. could D. need
Be careful with the knife, ______ you’ll be hurt.
A. so B. or C. but D. because
— ______ do you go to the gym?
— Twice a week
A. How often B. How soon
C. How many D. How long