Task 10 prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace> Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all these only if they are healthy. They must be well cared for to remain healthy. Your trees’ trouble may be you yourself. People spend much time and money to plant and maintain trees. Tree improves the looks of homes, parks, business, and public buildings. Yet, people who love trees the most may be the ones who cause them injury. Of course, they do not do this on purpose. They are most likely not aware of the kinds of things that injure trees. There are many people-caused tree injuries. You should become aware of them and avoid them. Learn the things that can help to keep your trees healthy. Healthy trees are beautiful. They make our world a pleasant place to live. Unhealthy trees are not as beautiful. They make the world less pleasant. Healthy trees help to cool and clean the air. They can even deaden ( 闷抑 )sound. Unhealthy trees cannot help or protect the environment. Trees, like people, are disturbed by changes around them. Construction of buildings is a major cause of tree injuries. 46. According to the passage, only_____ trees can give us shade and products.