In the world's first "Earth Day" since March 17, 1970, this event prompted the U.S. government to take some measures to control environmental pollution, accusing the U.S. government of a series of environmental pollution policies caused by the United Nations. Since April 22, 1970, about 20 million people across the U.S. participated in massive parades and assemblies aimed at raising people's awareness of environmental protection and rational use of resources in the sixties, this event prompted the U.S. government to take a number of measures to control environmental pollution. After April 22, 1969, Democratic Senator Gerald L. Nelson proposed the "Earth Day" campaign to hold mass talks on environmental issues in national parks. Since the 25th year of Harvard University, Harvard University students Dennis Hansen