英语语法分析

This paper describes a non - excavating construction machine - hydraulic perforator.

本文介绍了一种新型非开挖施工机械———液动穿孔机。

In this paper, tho design principles, structures and applications of the perforator.

本文简要介绍它的设计原理和结构及工程应用。

Perforation effect is seriously affected by the clearance between perforator and casing.

射孔枪与套管之间的间隙过大会影响射孔效果，太小容易出现工程事故。