原文∶如今，随着生态环境的不断改善，越来越多的鸟类在北京栖息。
译文∶Today， as continuous improvement of the ecological environment， more and more species of birds dwell in Beijing
改译∶
【正确答案】：Today, with continuous improvement of the ecological environment, more and more species of birds dwell in Beijing.（考点：介词的正确使用）
