51. 某英文報社正在舉辦題為“Let’s Save Water” 的征文活動。請就此題目寫一篇英文短文應征，內容包括：
With the rapid development of the national economy, a large number of environmental problems have appeared at the same time. One of the problems is water pollution and this situation is becoming more and more serious. In the past, the river was clean and there were many trees around us. However, in recent years, the environment around us becomes very terrible.
Water resource is very important for our lives. Therefore, we should take some measures to protect our water resource. Firstly, for government, should make relative polities to save water. Secondly, for heavy industry factories, shouldn’t throw the dirty water into the river. Finally, for citizens, should plant more trees to keep water and promotes more people to take part in this saving water activity.