阅读理解。 Trees are useful to man in three important ways. The first important way is that they provide (提供) 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. 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. 根据短文内容，选择正确答案。 1. How many important ways are trees useful to man? A. Two ways B. Three ways C. Four ways D. Five ways 2. Trees only provide man with food ,don't they? A. Yes they are B. No, they don't C. Yes, they do D. No, they aren't 3. On a hot summer, what do trees give us? A. They give us food on a hot summer day. B. They dive us wood on a hot summer day. C. They give us shade on a hot summer day. D. They  give us leaves on a hot summer day. 4. What does the underlined word 'they' means? A. The men who cut down trees in many parts of the world. B. The humans C. the men who enjoy the shade D. The men who enjoy the food 5. What's the best title for the passage? A. What is a Tree B. How to plant trees C. The Importance (重要性) of Trees D. How to protect Trees