Look at this picture. What is it?
看这张图片，它是什么？
It's the Earth.
是地球。
The green and brown parts are forests and land. What are the blue parts?
绿色和棕色的部分分别是森林和土地，蓝色的部分是什么？
I think they're oceans.
我想是海洋。
Yes, they are. The Earth was very clean and beautiful in the past, but now some parts are dirty. Can we do anything to help the Earth?
是的，它们是。过去的地球很干净漂亮，但是现在有些部分被污染了。我们可以做些事情拯救地球吗？
Yes. We should stop throwing rubbish into rivers.
是的，我们应该停止向河里扔垃圾。
We should stop cutting down so many trees.
我们应该停止砍伐这么多的树。
We should stop using plastic bags.
我们应该停止使用塑料袋子。