Among them this paper elaborated on each sub-system within the head-end system, explained the flow of the whole head-end.

其中详细说明了前端系统中各个子系统的组成，并说明了整个前端的工作流程。

youdao

To start the flow of oxygen, pull the mask towards you. Place the mask over your nose and mouth, slip the elastic strap over your head, tighten it by pulling the end of the strap.

氧气面罩落下后，请用力向下拉，罩在口鼻处，将带子套在头上，可通过带子调节松紧。

youdao

To start the flow of oxygen, pull the mask towards you. Place the mask over your nose and mouth, slip the elastic strap over your head, tighten it by pulling the end of the strap.

氧气面罩落下后，请用力向下拉，罩在口鼻处，将带子套在头上，可通过带子调节松紧。

youdao