Please answer the following question: Article: There's one language that is used in every country in the world. It's everyone's second language. It's easy to be understood, although you can't hear it. It's sign language. When you wave to a friend who is crossing the street, you're using sign language. When you raise your hand in class, you're saying, "I think I know the correct answer." Babies can point at things. They're using sign language. A policeman who wants to stop the traffic holds up his hand. He's using sign language, too. Sign language is a bridge between the deaf and non-disabled people. They use the movement of the hand, arms or body to express a speaker's thoughts. Today, in many countries, there are special TV news programs for deaf people. The news reporter tells the news in sign language. At the same time, the words appear on the TV screen. The actors in the theater for the deaf often use their hands to show what they want to say. They can make a roof with their hands over their heads when they want to show "house". One finger over a person's mouth can mean "quiet". You can talk to people behind closed windows. And when you go swimming with your friends, you can have a talk under water with sign language. Question: When one raises his hand in class, that means _ . Yes or no, is the answer "he may know the correct answer"?
A:
Yes