We have only one earth. But now, the environment becomes worse and worse. As you know, there's no enough clean water for people. So many of them lose their lives because of water. In a lot of countries, people have to cut trees for living. So there's nothing to keep water from running away. Also we have polluted the land, the river and the air. Some people may say: we are the masters of nature. Now the "master" seems to be confronted with problems that are far beyond his control.
the holes of the ozone layer make the earth less suitable to live for some creatures including human beings. Facing all the disasters made by ourselves, we have the responsibility to deal with the problem.
we must do something useful to protect our environment. We can plant trees and take good care of them. We can save the water and ask our parents to do so. We can't throw any litter onto the ground and we should collect them for recycling. If we take good care of our earth today, it will be more beautiful tomorrow。
我们只有一个地球。但是现在，环境变得越来越糟。如你所知，也没有足够的清洁饮水的人。所以许多人失去了他们的生命，因为水。在很多国家，人们不得不砍树的生活。所以没有什么能阻止水的流失。我们还污染了土地，河流和空气。有些人可能会说：我们是自然的主人。现在的“主人”似乎面临的问题远远超出他的控制。
臭氧层的空洞使得地球不再适宜于某些生物包括人类生活。面对着自己造成的灾难，我们有责任来处理这个问题。
我们必须做些什么来保护环境。我们可以种树，好好照顾他们。我们可以节约用水，并要求我们的父母这样做。我们不能把垃圾丢在地上，我们应该收集回收。如果我们好好照顾我们的地球上，这将是更加美好的明天。

---

　　my last weekend
last weekend,our class had an interesting out-class activity.
we had different kinds of activities.some students were interested in sports,they played basketball or table tennis.we also had some interest groups and clubs such as drawing,music,dancing,and computer groups.those who learn english well went to the english corner.
all my friends felt we had a wonderful time.we all had fun!what an unforgettable weekend!（
我最后的weekendlast周末，我们班有一个有趣的课外活动。我们有各种不同的活动。一些学生对体育感兴趣，他们打篮球或乒乓球。我们还有兴趣小组和俱乐部，如绘画，音乐，舞蹈，和计算机组。那些学好英语去英国角落。我所有的朋友都觉得我们有一个美好的时光。我们都玩得很开心！什么是一个难忘的周末！）

---

　　什么主题的？