权威例句
Population and the greenhouse effect.Urban stress test.Harvesting hope.ZPG 1983 population action guideElementary population activities kit.Global 2000 countdown kit [teaching module]A World of Six Billion Wall Chart and Activity Guide: Thought Provoking Activities on Population, Resources, and Our Environment.People, Resources and the Environment: Population Education for a Sustainable Future.Letter from Eugene V. Coan, Zero Population Growth, Inc. to Joshua Lederberg1. Zero Population Growth (ZPG) believes that the present population of the U.S. exceeds the optimum level for the continued well-be...