Be a Friend to TreesBy: Patricia Lauber Illustrator: Holly Keller Series: Let's Read and Find Out Science 2 Read and find out about trees in this colorfully illustrated nonfiction picture book. Why should you be a friend to trees? Trees are a valuable natural resource. People depend on trees for food, and animals depend on trees for food and shelter. But most important, we depend on trees because they add oxygen, a gas we all need, to the air. While trees give us many