The man has been in____ doctors describe as a vegetative(植物的) state for six years.
—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.