Air, or _______ is called the atmosphere, surrounds the whole world.
| A．what | B．which |
| C．that | D．it |
____ you promise to buy her a gift, you can’t break it in any case.
| A．Once | B．Until | C． For | D．That |
He realized she was crying ________ what he had sad.
| A．because | B．because of | C．as | D．since |
They said to us, “Are you afraid to leave this house ?”
They asked us ____ afraid to leave _____ house.
| A．that were we…this | B．that we were…that |
| C．if were we …this | D．if we were…that |
The number of people in their class _______51.
| A．is | B．are | C．does | D．has |
It was in New Zealand ______ Elizabeth first met Mr.Smith.
| A．that | B．how | C．which | D．when |