Americans buy more bottled water than any other nation in the world. 29 billion bottles of water are drunk each year. It takes 17 million barrels of oil to make these bottles. That's enough oil to keep a million cars going for twelve months.

So why don't more people drink water from the tap in the kitchen? Some people drink bottled water because they think it is better for them than water out of the tap, but that's not true. In the United States, the government makes sure water from the tap is safe.

People love bottled water because it is convenient to take with them. But maybe if they understand the problems it makes, they will try drinking from a glass at home or carrying water in a reusable bottle instead of a plastic one. Although plastic water bottles can be turned into some other useful things, only a small number of them are reused. The rest are taken away in rubbish trucks, or even worse, they end up as rubbish on the land and in rivers, lakes, and the ocean. Plastic bottles take hundreds of years to break down.

Water is good for you, so keep drinking it. But think about how often you use plastic water bottles, and see if you can make a change. If you take one to school, don't throw it away — bring it home and put tap water in it for the next day.

“Look! The community center is having an art contest,” said Grace. She was holding a flyer (传单).

Mrs. Simon read the flyer aloud. Everyone agreed they would like to enter the art contest. Mrs. Simon said, “Our classroom supply (供应) of art materials is low because it’s the end of the year. I’ll check with Mrs. Rice to see what she has.”

Mrs. Rice, the art teacher, didn’t have any art materials. “I won’t be getting a supply until next year,” she said. The whole class was upset. “How can we enter the art contest without art materials?” asked Grace. “Maybe we can raise the money. We could have a bake sale,” suggested Hal.

“I don’t think there is time,” Mrs. Simon said.

“Let’s use the paper in the recycling bin. When we use recycled paper, we use natural materials and save trees.” said Pablo. “We can also use this old string (金属线) and these wire hangers (铁丝衣架),” added Grace.

Now the class had to decide what to do with the materials. Pablo had another idea. “We can fold the paper into the cranes (鹤).” Mrs. Simon taught the children how to fold a paper into cranes. Then everyone helped tie the cranes to a frame (架子) to make a mobile. On the day of the contest, the paper crane mobile hung in a large community center room. The huge space was crowded with art works. The crane mobile swayed (摇摆) gently as people walked past, the paper cranes appeared to be softly flying. The paper crane mobile won the prize for the most creative use of materials. “We were so glad,” Grace said, “We made our art work, and we saved the Earth at the same time.”

What will the houses of the future look like? Could it have gardens on its walls, or a pool with fish for dinner? Architects(建筑师)believe that they are all possibilities. The only thing for sure is that the houses will be as green as possible.