The paper has summarized systematically evolutionary law in time and space on petrofacies and paleogeography of Late Paleozoic era in Northern China and distributive law of depositional systems.

根据华北晚古生代沉岩的环境标志,出29个相,归并为冲扇、河流、三角洲、潮汐砂滩、碳酸盐台地等6个沉。

Performation of surgical procedures anterior to ethmoid bulla can avoid risks of the other models, therefore, endoscopic frontal sinusotomy in the route anterior to ethmoid bulla is a safe model.

结论通过鼻内镜对窦开口及周围解剖结的观察，认为星状裂作为恒定的解剖标志是窦开口的关键区域。筛泡前径路是鼻内镜下窦开放的安全入路，能避免其他径路存在的某些风险。