There can be one, two or three joints of casing used for this purpose.

为满足这一目的，可能需要放置一根、二根或者三根浮动接头。

youdao

There can be one, two or three joints of casing used for this purpose.

为满足这一目的，可能需要放置一根、二根或者三根浮动接头。

youdao