Water is the most common substance(物质) found on the earth, but less than 1% of the earth’s water is suitable for drinking. More than 1,000,000,000 people around the world survive on just over 1 gallon of water a day. Probably more than 3,000,000,000 people may suffer from not having enough water by the year 2025.
You are considered lucky if you live in a country where you can drink water out of your kitchen tap or bathroom tap. People in some countries have to pay for drinking water at home. So clean water is one of our most valuable natural resources(资源).  In fact, people waste(浪费) so much clean water today. In factories lots of water is wasted. At home many people are not taking showers but still baths, and many are brushing their teeth with the tap turned on. Children are no longer taught how to save water.
You can save clean water in many ways. For example, if you keep gold fish, the tank water excellent for garden plants. And when you wash a milk bottle, pour(倒) the water on your house plants. Putting a brick into your toilet tank may help use less water, saving many gallons over a long time.
Using rainwater is another simple way to save clean water. You can use rainwater to wash your hands after gardening, flush the toilet, and wash your car, your pet, your driveway when they are dirty.  For the same reason, people in Malaysia are encouraged to use rainwater. If one has a house with a small garden, he would buy a huge plastic tank to keep rainwater for their daily life.
According to the passage, one of the ways to save water is _______.

A．to stop keeping gold fish

B．to pay much for drinking water

C．to use it in a clever way

D．to educate those who waste water

The underlined word “flush” means “_______”.

A．clean something with water	B．pour water over something
C．make something wet with water	D．get water out of something

People are encouraged to use rainwater _______.

A．so that is can make our life easier

B．so that clean water can be kept for other uses

C．because it is free and easy to get

D．because there is no clean water left for them

We can learn from the passage ______.

A．when man can’t live without water

B．where there is no water resource

C．why there is less water on the earth

D．how important it is to save water