文档介绍：英语:
Plants and animals, including humans, need food and water to live on. These are from the natural resources(资源) on Earth. To protect these resources, we need to keep the air clean and the water drinkable. We need to keep the soil (土壤)healthy. How do we do that?
Protect the land
The soil that covers fields and farms provides much of the food we eat. Human activities such as plowing(耕) fields, mining(采矿), and building highways can destroy (破坏)the land. Erosion happen when wind and water carry away the soil. Soil erosion can turn rich farmland into a desert wasteland. So does this mean we shouldn’t build a highway or plow a field? Of course not. But it does mean we might think about Earth—friendly ways of doing those things.
Today farmers plow their fields in different ways to prevent erosion. They try to use less water for their crops. They keep animals from eating the growing grass in just one area. Farmers also plant trees to prevent erosion from happening.
Save the Trees
Another human activity that damages the land is deforestation(采伐森林). People take away a large number of trees from a forest. Millions of square kilometers of forest disappear each year. When this happens, many plants and animals lose their places to live. They may die out, or e very few. Scientists haven’t even discovered all the living things in the forest. We may be losing some without even knowi