Trees are useful to man in three ways. Firstly, they provide man with food, wood and other products. Without trees, animals could not live on the earth.
　　Secondly, trees can give us shade. On a hot summer day, people can have a rest under the shade of a tree after they have walked a long way.
　　Thirdly, trees help to prevent drought and floods. If we cut trees down in large numbers, we will lose the best friends in the world.
【參考譯文】
　　樹對人的益處有三個(gè)方面。首先，它們給人類提供了食品、木材及其他產(chǎn)品。如果沒有樹，動(dòng)物無法在地球上生存下去。
　　其次，樹給我們樹蔭。在炎熱的夏天，人們在走了很長的路后可以在樹蔭下休息。
　　第三，樹有助于防止旱災(zāi)和水災(zāi)。如果我們大量砍伐樹木，我們會(huì)失去世界上最好的朋友。