螺丝盖子已经在管筒的顶部安装到位，管筒的下端开口以便于填装过程。

The screw cap is already in place at the top of the tube and the lower end is open for the filling procedure.

youdao

螺丝盖子已经在管筒的顶部安装到位，管筒的下端开口以便于填装过程。

The screw cap is already in place at the top of the tube and the lower end is open for the filling procedure.

youdao