Don't leave the water ____ while you brush your teeth．
| A．run | B．running | C．being run | D．to run |
It is these poisonous products_____can cause the symptoms of the flu , such as headache and aching muscles .
| A．who | B．that | C．how | D．what |
—Your hometown is so beautiful!
—Yes. What's more, _ _____ we live there is fresh air there is no in town.
| A．that | B．whether | C．where | D．when |
--- Tom, how about going for a picnic this weekend?
--- _________. I love getting close to nature.
| A．I’m afraid not | B．I couldn’t agree more |
| C．It’s well done | D．I don’t think so |
I was really anxious about you. You ______ home without a word.
| A．mustn’t have left | B．shouldn’t have left |
| C．couldn’t have left | D．needn’t have left |
Wilma became the first American woman to win three Olympic gold medals in track, ________ made her mother very proud.
| A．it | B．that | C．which | D．this |