There is one language, and people, young and old , men and women, use it very often, in every country in the world. It is everyone's second language . You can't hear it, but it is very easy to understand . It is sign ( )language. When you wave to a friend in the street, you are using sign language. When you put up your hand in class, you are saying "Please ask me, I think I know the right answer". When a police officer wants to stop cars or buses, he puts up his hand. He's using sign language. Churchill's famous "V  for Victory "is also sign language. Sign language is useful in quite places full of noise  . Even when you are swimming with your friends , you can have a talk under water. When you put up your hand in class, you mean  _  .
you can answer the question you want to write a question you can use sign language both A and B