Subject four is also called subject three, and common sense of safe and civilized driving is also called subject four theoretical examination and driver theoretical examination, which is a part of motor vehicle driver's license examination. After the implementation of OrderNo.. The Ministry of Public Security of the People's Republic of China 139, subject 3 exam is divided into two contents. In addition to the road test, the common sense test of safety and civilization has been added, commonly known as subject 4, considering vehicle ethics. Because this exam is conducted after subject three, everyone is used to calling it subject four exam. Actually, there is no subject four in the official statement. The examination paper consists of 50 questions, which are mainly presented in the form of cases, pictures and animations. , full score 100, qualified 90 points.