中山市在回归自然生态环境的进程中最值得一提的是被誉为城市之肺的五桂山脉。
B-Location I-Location I-Location O O O O O O O O O O O O O O O O O O O O O O O B-Location I-Location I-Location I-Location O B-Location I-Location I-Location I-Location O