英语语法分析

Causes of ectopic fetation in 399 patients were retrospectively categorized and analyzed.

399例患者异位妊娠的原因被回顾性分类并分析了。

Methods Causes of ectopic fetation in 399 patients were retrospectively categorized and analyzed.

方法：采取回顾性分析的方法，对399例异位妊娠的病因进行分类。

Due to eyes characters of anatomical structure and optical function, it plays more important roles in eyes stasis, fetation, differentiation, proliferation and tumor incidence.

由于眼组织功能和解剖结构的特殊性，使得这一结构在眼的稳态、胚胎发育、分化增殖，乃至肿瘤的发生方面起着更为重要的作用。