Steel pipe is the most common, but fiberglass pipe, cement-lined steel pipe, and flexible plastic pipe are also used.
2
由于本发明的设计非常简单,因此可以用柔性塑料材料制造它和用此装置作为一次性系统。
As the design of the invention is very simple, it is possible to manufacture it with flexible plastic material and use the apparatus as a disposable system.
3
PVC不是一种柔性的塑料,因此要加入一种叫邻苯二甲酸盐 的化学物质,使它变的更柔软。
To begin with, it's not a soft plastic, so phthalates are added to make it more pliable.