Volunteers distribute leaflets highlighting the importance of environmental protection in the border city Heihe in northeast China's Heilongjiang Province, on Wednesday, June 4, 2008, one day ahead of the World Environment Day. World Environment Day is one of the principal vehicles through which the United Nations stimulates worldwide awareness of the environment and enhances political attention and action. The World Environment Day slogan for 2008 is" Kick the Habit! Towards a Low Carbon Economy."[Photo: northeast.cn]