—I wonder why Sara looks worried today.
—I'm not sure，but she a small accident driving here.
| A．could have | B．might have |
| C．might have had | D．must have had |
—Would you like to come to dinner tonight?
—I’d like to, ___ I’m too busy.
| A．and | B．so |
| C．as | D．but |
It shocked me to see ______ my neighbors treated their children.
| A．why | B．whether |
| C．how | D．since |
—I don’t like chicken _______ fish.
—I don’t like chicken, _______ I like fish very much.
| A．and, and | B．and, but |
| C．or, but | D．or, and |
We were just about ready to leave _____ it started to snow.
| A．when | B．before |
| C．after | D．since |
_____ the government agrees to give extra money , the theatre will have to close.
| A．Until | B．Unless |
| C．Since | D．While |