提示：1）树可以为我们提供很多有用的东西，如水果、药品、木材等；2）树可以为人类提供氧气，净化空气，美化环境；3）树可以为动物提供家园和足够的食物，保持大自然的平衡（the balance of nature）；4）树能够防止水土流失和土地变成沙漠（desert）。

The uses of trees

    For humans, trees have a lot of uses.

—Because cold weather is (harm) to them.

We shouldn't trees or trees will.

China is a country .

    Many peoplethe rainforests of the world and most of them do not hurt the forest they live in. They eat the fruits on the forest trees, but they do not.

    When we cut down the trees, we destroy these forest people too. In 1900, there were about 1,000,000 forest people in the Amazon rainforest. In 1980, there were only around 200,000 left.

    The Yanomami live in the Amazon rainforest and they use20,000 different plants for food and medicine. But in 1988, someone found gold in their forest, and suddenly 45,000 people came to the forest and begangold. They cut down the forest to make roads. They made more than a hundred airports. The Yanomami lost the land and food. Many diedthe new diseases brought by the strangers.

    The goal of World Wide Fund (WWF) is to save the world's environment. The organization was set up1April 29, 1961. In the beginning, WWF worked2the world's wildlife. Now, it works to save the Earth3its environment.

    WWF has many tasks. One is to stop air pollution. Pollution from industry (工业) and cars is4to our environment. Each year, more and more trees are cut down,5WWF tries to protect Earth's forests. Also WWF is interested in saving all plants and animals. As people use more land, more and more animals6their homes and many die. WWF can buy important areas7the land from disappearing because of humans' development.

    WWF has many projects. In China, WWF works to save pandas from extinction (灭绝).8South America, it works to save the Amazon rainforest.

    Volunteers and donations help WWF complete its work. WWF's work is9to our environment, and it is also important for people to help it10time and money.