With industries and business developing quickly, the number of trees in many big cities has dramatically reduces. Efforts are being made to prevent people from cutting more trees. But a lot of trees are being destroyed by people who have never thought of the importance of green plants.Making cities greener has many advantages. First, it can make our air cleaner. Some researchers have proved that trees can reduce the amount of carbon dioxide in the atmosphere through absorption. Second, it can make our cities more beautiful. With trees and flowers everywhere, living conditions can be improved.

　　Finally, it can produce timber—-an effective way to solve the problems of limited supply of natural resources.Making our cities greener requires nationwide efforts. People in every field should not only know about the importance of keeping the quality of urban environment, but also take common action to plant more trees and flowers so as to improve our living conditions.

翻譯：

隨著經濟的快速發展，樹木的數量在許多大城市里已經急劇減少。正在作出努力防止人類砍伐更多的樹。但許多樹木正在被那些永遠不會想到綠色植物重要性的人摧毀著。綠化城市有許多優點。第一，它可以使我們的空氣更加清新。一些研究人員已經證明，樹木可以通過吸收減少大氣中的二氧化碳量。其次，它可以使我們的城市更加美麗。樹木和鮮花遍地，生活條件得到改善。

最后，它可以生產木材—-一個有效解決有限自然資源供應問題的方法。使我們的城市綠化需要全國的努力。在各個領域的人們不應該只知道保持城市環境質量的重要性，而且還采取共同行動，種植樹木和花草，以改善我們的生活條件。