Liu Xu is a student from a middle school in Guangxi. Once he was riding home when a  robber   suddenly jumped out from the roadside. He pulled Liu Xu off his bike and rode away. Liu Xu was scared, but he didn't run after the robber. He found a telephone and called the police at 110. "Safety is the first important in such a situation," Liu said, remembering what his teacher had told him in his first aid class. "It is not safe to run after an adult who is stronger than you." Liu's school has compulsory   first aid education. Students must take the class once a week. Teenage safety has become a serious issue recently. According to a survey, about 16,000 teenagers die in accidents in China every year. At Liu's school the first aid classes are to "teach students skills how to protect and save  themselves in emergencies  ". Students there often learn by role-playing in first aid classes. For example, one student performed as a stranger knocking at a door. Another one stood inside the door and asked several questions before letting the "stranger" in. Then they changed roles and did it again. They learned a lot while having fun at role-playing. The topics of the first aid classes are regularly updated  . The students have learned skills for surviving in earthquakes. The teacher also taught the students not to go out at night. If someone tried to do bad things to them, they should quickly run into crowed place. What did Liu Xu remember when he met the robber?
Safety is the first important. How to run away from an earthquake. To run after the robber quickly. Not to go out at night.