To improve performs of engine, the piston skirt curve is designed to be middle convex and varied elliptic pattern, copying manufacturing with master piston is commonly used.
为提高工作性能，活塞裙部设计成中凸变椭圆型，立体靠模仿形车削是常用的加工方法。
To comprehend this sentence pattern perfectly, one should have a clear demarkation among the easily confusing conceptions of imperative sentence, elliptic sentence and so on.
要完整地理解无主句，必须弄清楚祈使句、省略句等易于混淆的概念。
应用推荐