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阅读理解
Have you ever really looked at a tree? All trees are big plants. Like all plants, trees have roots. The roots hold trees in the ground. They keep trees from falling over. They bring water and food that trees need to live on.
A tree has a fat stem. We call the tree's fat stem "trunk". Inside the trunk, a tree holds water and food. The water and food go up through the trunk to the green leaves. The leaves use sunlight to make more food for the tree.
Trees help us. They help clean the air. They give us food. Fruits, nuts and chocolate all come from trees. Paper, chairs, beds and houses also come from trees. Trees are also important for other living creatures (生物). They provide a home for birds and other animals. Many animals eat part of trees. Be friends with trees! We need trees and trees need us! Often young trees need special care. They need water and protection (保护).
