英语语法分析

Study the characteristics of the color Doppler echocardiography of ruptured mitral chordae tendineae (RMCT).

研究二尖瓣腱索破裂（RMCT）的彩色多普勒超声心动图特征。

The objective is to explore the roles of color Doppler vena contracta in the evaluation of mitral regurgitation grading.

目的是探讨彩色多普勒静脉收缩术在评估二尖瓣反流分级中的作用。

Their organs are so similar to our own that pig heart valves are used to replace human aortic or mitral valves.

她们的器官和我们的是如此相似，以至于心脏瓣膜被用于人体主动脉瓣或二尖瓣替换手术。