(上海)牛津版九年级上册
The tropical rainforests of the world are in South America, Africa and Southeast Asia. There are millions of trees growing close together. In order to get more sunlight, some trees there grow up to 50 metres tall to catch the sunlight.
Throughout the world, trees are being killed by acid rain. This is caused by pollution from cars and factories. The rain that falls on trees damages their leaves and stops them from growing properly.