英语语法分析

Epidemiological studies have found that children with PDD have no higher prevalence of gastrointestinal tract than normal children.

流行病学研究发现，广泛性发育障碍（Pervasive Developmental Disorder）孩子和正常孩子相比较并没有更高的胃肠道患病率。

This will allow the robot to crawl around the gastrointestinal tract, perform treatment with appropriate surgical tools, and perform biopsies.

这将使机器人可以在胃肠道周围爬行，用适当的外科手术工具施行治疗，且可以进行活体组织检查。

The solubility, stability in gastrointestinal tract, membrane permeability and presystemic metabolism of drugs were the major factors on oral drug absorption.

药物的溶解性，在胃肠道中的稳定性，膜的通透性和全身代谢是影响口服药物吸收的主要因素。