差距·机遇·挑战──从国外大城市的森林环看北京市区的绿化隔离地区范耀邦令人羡慕的“森林环”在城市建设方面，我们与发达国家相比，有许多方面存在不少差距，其中之一是城市外围的环境质量。国外许多现代化大城市的外围都有大片森林环绕，有的森林“楔入”城市，使市... Gaps, Opportunities, and Challenges - Looking at the green and isolated areas in the Beijing area from the forest ring in major foreign cities Fan Yaobang’s enviable “forest ring” in urban construction has many aspects compared to developed countries. One of the gaps is the quality of the environment outside the city. The periphery of many modern large cities in the world is surrounded by large forests, and some forests “wedge” cities to make cities...