准入

A mountain creates biotopes and eco-niches, it channels water and stores heat, it provides viewpoints and valleys, access and shelter.

山区创建群落生境生态位，它渠道水热量商店，它提供观点山谷，准入。

The mechanism of the conventional medical endoscope in our country is introduced here, and its safe and effective performance is discussed in regard to requirements in premarketing evaluation.

介绍国内市场上常见医用内窥镜工作机理,结合目前市场准入要求类产品安全性有效性技术指标进行了探讨。