英语语法分析

The goat embryo re-acted the process of the system evolution, which passed through pronephros, mesonephros and metanephros.

山羊胚胎重新反应了系统进化的过程，该过程通过前肾，中肾和后肾。

The development of the kidney, the major excretory organ after birth, consists of 3 stages:the pronephros, mesonephros and metanephros.

肾脏是人体主要的排泄器官，它的发育经过原肾、中肾、后肾3个阶段。

Objective: to observe the development of mesonephros and the expression of growth factors and their receptors in human embryo of 3th-8th weeks.

目的：观察第3 ~ 8周人胚中肾的发育和生长因子及其受体的表达。