There aren’t many seats left for the play; you had better make sure that you________two today.
According to the latest research, getting enough sleep is _____ to maintaining good health and reducing stress.
He _____ be really difficult at times even though he ,generally speaking, is a nice person.
John received an invitation to dinner, and with his work ________, he gladly accepted it.
You can only be sure of_________ you have at present; you cannot be sure of something _____ you might get in the future.
—Could you turn the TV down a little bit? —________. Is it disturbing you?