The cause of the epidemic. Peking University, Tsinghua said that the reason for the suspension of classes was the epidemic, so the classes were temporarily suspended. Tsinghua University, referred to as "Tsinghua" for short, is a national key university directly under the Ministry of Education and the Central Government of People's Republic of China (PRC), ranking among the national "Double First Class", "2 1 1 Project" and "985 Project". The nine-school alliance, Song Lian alliance, China University Presidents Association, Asian University Alliance and Pacific-Massachusetts Institute of Technology Alliance were selected for "201/plan", "Everest Plan", "1/plan" and "Strong Foundation Plan" respectively. It is also an important base for China's high-level personnel training and scientific and technological research, and is known as the "cradle of red engineers".