Fifty thousand words. Beijing Normal University is a national key university directly under the Ministry of Education of People's Republic of China (PRC), which is jointly established by the Ministry of Education and Beijing. Ranked as "Double First Class", "985 Project" and "2 1 1 Project", it is one of the first ten key construction universities in the Seventh Five-Year Plan and the Eighth Five-Year Plan. As a member of China University Planetary Science Alliance, Jinggang University Alliance and Guangdong-Hong Kong-Macao Greater Bay Area Logistics and Supply Chain Innovation Alliance, the number of doctoral dissertations and monographs on environmental science in Beijing Normal University is 50,000 words, as long as it is more than 50,000 words.