Some people say dolphins （海豚）are smart like humans （人类）. They can think, understand and learn things quickly. In fact, dolphins have big brain （大脑）-to-body size ratio （比例）, which is second only to humans. Dolphins use brains differently from the way humans do. But scientists say dolphins are like humans in some ways. How?
Like humans, every dolphin has its own “name”. The name is a special sound. Each dolphin chooses a special sound for itself at birth. Dolphins are like people in other ways, too. They “talk” with others in their own groups about a lot of things—such as their age, and how to find food. They also use sounds and body languages to talk. Understanding dolphin words is not easy for humans. No one speaks dolphin words, but some scientists are trying to learn.
Dolphins are also social （社会） animals. They live in groups, and often join others from different groups to play games and have fun—just like people. Scientists believe playing together is something only smart animals do.
Both humans and dolphins make plans for getting things they want. For example, when there are fish near a boat, dolphins jump high to ask the fishermen to put their nets （网）, and then the men can catch a lot of fish. Why do dolphins help the men? Because they can get some fish that run away from the net.
【小题1】Dolphins can think, understand and learn things quickly, because of ________.| A．big body | B．small brains |
| C．big brain-to-body size ratio | D．small body-to-brain size ratio |
①They have names.
②They play in groups.
③They can talk with other kinds of animals.
④They can make plans to get things they want.
| A．①②③ | B．①③④ | C．①②④ | D．②③④ |
| A．To get some fish. | B．To run away from the net. |
| C．To put the nets. | D．To jump high. |
| A．Smart Animals Can Talk. | B．Dolphins Help Humans. |
| C．Dolphins Like Humans. | D．Dolphins Are Like Humans. |
