Relax yourself every day,________ you'll be too tired to get good grades.
—May I put my luggage on the seat beside you, sir?—_________________.
—How much do I owe you for lunch? —________________. It’s nothing.
It ________ that their plan was practical and successful.
It is considered a good way for students to ________study with pleasure.
It is known to all that a proper amount of exercise ________ to good health.