There's one language that people use in every country. People, young old, short and tall, use it very often. It's (everybody) second language-sign（手势）language.
you wave your hand in the street, you are saying "hello"to your friend. When you put up your hand in class, you are (tell)the teacher that you know the answer. When a policeman (want) to stop cars or buses in the street, he raises his hand. All of (they) are using sign language. In some (place), you have to use sign language to talk with others. For example, when you are swimming your friends, you can have a talk under water by(use) sign language. an interesting language!
