Teacher Liu Zejian of Global Network School is a national registered geotechnical engineer, a senior engineer and the chief engineer of Huasheng Company of China Coal Administration. As an expert in geotechnical engineering in North China, he once served as a report reviewer of a large-scale geotechnical control project. He has many years of practical experience in geotechnical engineering and hydrogeological engineering. Now he is an online teacher of global vocational education and a lecturer of registered engineer course.