John _____ such a thing about you. He never speaks ill of you behind your back.
| A．can’ t have said | B．might not say | C．couldn’ t say | D．mustn’ t have said |
Theof surfing the Internet is how you can tell whether the information is true or not.
| A．ability | B．competition | C．challenge | D．knowledge |
Gun control is a subject_____ Americans have argued for a long time.
| A．of which | B．with which | C．about which | D．into which |
Ladies and gentlemen, please remain_____ until the plane has come to a complete stop.
| A．seated | B．seating | C．to seat | D．seat |
As is often said, a friend is to man_____ water is to fish.
| A．what | B．as | C．that | D．which |
To his disappointment, the opinion he had held____ out wrong.
| A．turned | B． turning | C．has been turned | D．has turned |