第7题：
问答题
Many parts of the world are losing important natural resources, such as forests, animals, or clean water. Choose one resource that is disappearing and explain why it needs to be saved. Write a composition of about 400 words on the topic.
正确答案：
SAVING TREES ON OUR PLANET Many natural resources are being wasted on our planet every day. One of the most important resources we are abusing is our trees. Each year, hundreds of thousands of acres of trees disappear in countries all around the world. In some countries, trees are used for fuel. In other countries, trees are destroyed to build houses and shopping centers. Saving trees has become a major cultural and economical issue in many parts of the world.
Trees are essential to our survival. They are a major part of the process of photosynthesis. Photosynthesis is the process in which green plants use carbon dioxide to produce oxygen, and oxygen is something all of us need. The fewer trees there are, the more this affects our ability to breathe.
In rural areas, farmers have always known how important trees are to soil conservation. This is why you'll usually see trees lining a field. Tree roots help keep the soil in place, and are also a factor in water distribution deep beneath the ground. They help to prevent drought and floods. Unfortunately,in many parts of our country,people haven't realized the importance of trees. They cut them down at will. They are usually too lazy or too careless to plant and look after new trees. As a result, the forests continue to disappear. Where there are no trees the rain falls on the surface, causing floods, and carries away with the rich topsoil, in which crops grow so well. When all the topsoil is gone, nothing remains but worthless deserted.
Trees are also important in the development of many medicines. The mainstream medical establishments did not recognize this for many years. However, those who use natural medicines have always known how important trees are. Many drugs come from the leaves of certain trees, along with other herds and plants.
Finally, we should save trees from disappearing because they provide so much pleasure. I think that I shall never see a poem as lovely as a tree, wrote a poet. That is the truth. A tall, stately tree is beautiful to look at, and pleasing to the soul. It is also a great place to find shade on a hot summer's day.
For practical and emotional reasons, we need to preserve our planet's trees.
解析：
本题要求选择一种正在消失的自然资源并解释为什么要保护。范文作者选择了树木，在第一段描述了森林消失的状况。第二、三、四、五段分四点说明了树木对人类的重要性。最后一段用一句话总结了中心思想。
