There are more than 400 kinds of sharks all over the world. 全世界有400多种鲨鱼。

　　Because sharks eat large fish, they are the top of the food chain in the sea. 因为鲨鱼捕食大鱼，所以它们处于海中食物链的顶端。

　　Sharks vary in size. 鲨鱼的大小各异。

　　The smallest sharks are 8 inches and the biggest sharks are 60 feet. 最小的鲨鱼长8英寸（约20厘米），而最大的鲨鱼有60英尺（约18米）长。

　　Some sharks attack humans. 有的鲨鱼会攻击人类。

　　These types are usually great white sharks, tiger sharks and bull sharks. 它们通常是大白鲨，虎鲨和牛鲨。