As we all know, trees are useful to humans and animals. They give living places and food to wild life. They take in carbon dioxide （二氧化碳） and give off oxygen（氧气）. They also make our world more beautiful. Let's know about some kinds of trees in the world.
Mulberry tree （桑树）
Mulberry trees come from China. Silkworms like to eat their leaves. Chinese people began to keep these worms and make silk about thousands of years ago. The silk went out through the Silk Road and made China famous.
Gingko （银杏）
The gingko is from China. And this kind of tree only grows in China. The life of a gingko tree can be very long—even thousands of years. In autumn, the gingko leaves turn yellow and look like beautiful small fans.
Eucalyptus （桉树）
The eucalyptus is from Australia. It is one of the most common trees in the country. Australians see the eucalyptus as their national tree. It can grow well in different places. People use it to make paper and build houses.
