Reliable. It is very reliable to cover all the basic knowledge and methods of high school, allocate them to every day reasonably, and complete the curriculum of high school mathematics within 30 days of the operation of the center of mass. Centroid education finished high school mathematics in 30 days and got high marks. In 30 days, we didn't just skim the water, but learned all the knowledge of high school mathematics systematically and completely. With different learning methods, higher, better and more practical problem-solving skills.