Earth Day is the largest, most widely celebrated international environment event. Earth Day helps celebrate Earth’s unique place in the universe. It is the only planet in our solar system with incredible biodiversity. Learning about and protecting this biodiversity is what Earth Day is all about. People all over the world celebrate our efforts to protect plants and animals and to clean up the world we live in. Gaylord Nelson of the United States founded Earth Day. Earth Day was first celebrated on April 22, 1970 in the United States. Across the United States, 20 million people and thousands of local schools and communities participated in the first Earth Day. It was made an international celebration by the United Nations the next year. Earth Day reminds us that we all share the same planet. Sharing Earth means taking responsibility for what we use and how we use it. It is a day to think of the environmental challenges we face and how to solve them. Protecting Earth is every person’s and every country’s responsibility. 请判断正误:In 1972 Earth Day was made an international celebration by the UN.