ISBN-13: 9780064451208 / Angielski / Miękka / 1994 / 32 str.
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 wonderful products, we must also protect them because we can't live without them.