在乒乓球运动中，一般来说，颗粒朝上，高度超过1.5毫米以上的胶皮称为长胶。这种胶皮的胶粒很软，颗粒细长，支撑力小。
使用长胶比使用反胶更难打出高质量的球。
Doing high quality shots is much more difficult than with inverted.
有一些人说，发球需要时间学习，而长胶却可以直接购买。
Some players complain that the difference is that serves have to be learned, and long pips just can be purchased.
文中介绍了膨胀式长胶筒封隔器的结构、工作原理及用于钻井、完井的应用情况。
This paper describes its structure, working mechanism, and field using in drilling and completion.
应用推荐