Many animals use some special kinds of "language" to communicate(交流) with each other. They use signals(信号) and the signals have their own meanings.

For example, when a bee has found some food, it goes 1 its home. It is2 for a bee to tell3 bees where the food is by speaking to them, but itcan do a little dancing. This tells the other bees where the food is and4 it is.

Some animals show how they feel by making sounds. It is not difficult to tellthat a dog is angry 5 it barks. Birds make several different sounds and 6 has its own meaning. Sometimes we humans make sounds 7. We make sounds like "Oh!" or "Ouch!" to show how we feel about something or when we 8 something on our feet.

We humans have languages. We have words. These words have the 9of things, actions(行动), feelings or ideas. By writing down words we can 10  what has happened or send messages to people far away.