Why did various social thoughts flood into China during the May 4th Movement?

. 1. The outbreak of World War I and the international situation had a great influence on China. 2. After the Revolution of 1911, "saving the country by industry" and "democracy * * * and" became two major ideological trends at that time. 3. The development of national capitalism (the National Government encouraged industry and commerce, and World War I ushered in the golden age of China's capitalist development), and the economy developed. 4.5. The New Culture Movement has shaken the dominant position of traditional culture; 6. The rule of the Northern Warlords was unpopular, which made the imperialist powers step up their aggression; 7. China people seek the idea of saving the country; 7. The ranks of the proletariat have grown, and the level of proletarian struggle has improved; 8. The loose ideological management adopted by the National Government made different ideas spread in China (which can answer the inner spirit of the Three People's Principles).