Cars make our lives convenient, but they can also be a problem. To improve the environment, many countries are developing electric vehicles (EVs). Among them, China is taking a leading role and has created the world’s largest EV market.

Last year over 40% of the 753,000 EVs in the world was sold in China. That was more than twice as those sold in Japan. Chinese young drivers are big fans of EVs. Some Chinese companies are among the top in the world’s EV sales.

“Charging an electric car is cheaper than a car with gas,” said Wu Hao, a driver who bought an electric car this year.

However, there are still some problems. It can be hard to find charging piles (充电桩) and the cars can’t go far before needing to be recharged. Some of these problems are being solved. But we still need more charging piles in some places.

China promised to stop increases carbon dioxide emissions (碳排放) by 2030. Developing EVs is one of many effects China has made to reduce pressure on its environment. As China goes, so will the world car industry.

In the 13th century, Marco Polo saw many wonderful things in China. One of the things he discovered was money made of paper. People in the West did not have such kind of money until the 15th century. However the Chinese began to use it in the 7th century.

Paper was invented by a Chinese man called Cai Lun almost 2,000 years ago. But it was not made in Europe until the year 1100. Four hundred years later, a German discovered that he could make the best paper from trees. After that countries rich in forests, such as Canada, Sweden, America, Finland became the most important ones in paper making.

Paper can be used in many ways. The common uses include newspapers, magazines and books. But do you know that paper can be used for keeping warm? In Finland, the farmers wear paper boots to keep their feet warm in the snow. And even houses can be insulated (使绝缘) from heat or cold with paper.

However, we have to understand that paper still comes from trees now. If we keep on wasting so much paper, there will not be any trees left on the earth someday in the near future. Every day people throw away about 2,800 tons of paper in our city. It takes 17 trees to make one ton of paper. This means that we are cutting down nearly 48,000 trees every day. The fact is that it takes more than 10 years for a tree to grow.

So we must start saving paper right now. We can use both sides of every piece of paper. We can make useful things out of used paper. We can use china cups instead of paper ones. When shopping, we can use fewer paper bags and reuse them if we have some.

In short, we should keep a balance between using paper and protecting trees, and do it now before it is too late.