--Are you Tom?
-- . Tom is my brother.
| A．No, I’m not | B．Yes, I am |
| C．Yes, it is | D．No, it is |
Although he is very old, ______ he works very hard.
| A．so | B．but | C．and | D．/ |
We decided ______at home _____ the bad weather..
| A．staying ; because | B．to stay ; because of |
| C．staying ; because of | D．to stay; because |
—____ do you exercise?
—Four times a week
| A．How much | B．How often |
| C．How long | D．How many |
—How was the weather yesterday?
—It was terrible. It rained ____. People could ____go out .
| A．hardly; hardly | B．hard; hard |
| C．hard; hardly | D．hardly; hard |
Twenty-five percent of the water in this river _____ dirty in the past.
A. is B are C. was D. were