学进去

Trees are useful to man in three important ways.

The first important way is that they provide man with wood and other products. Trees provide not only man with food, but also many animals with food. Without trees, many animals could not live on earth. It’s not easy for man to live on earth, either.

The second important way is that trees give us shade（阴凉）. On a hot summer day, people are eager（渴望）to have a rest under the tree after they have a long walk. You can imagine how important the shade of a tree is to man and animals.

The third important way is that trees help to prevent droughts and floods（防止干旱和洪水）. However, in many parts of the world, man hasn’t realized the third way. They cut trees down in large numbers. In the end, they find that they have lost the best friends they had.