Unit 2Task 1:【答案】June 5th，the United Nations，1972，world leaders and citizens how to protect the environment， San Francisco, California，Plan the Planet，Green Cities，most people now live，more than 75 percent，the former vice president，music concerts，parades，tree plantings，representatives from many environmental organizations【原文】Every year on June fifth many countries celebrate World Environment Day. The United Nations established this special day in nineteen seventy-two to get people
