Every time you breathe, air travels down the trachea, through a series of channels, and then reaches little clusters of air sacs in the lungs. These tiny sacs facilitate a crucial exchange: allowing oxygen from the air we breathe into the bloodstream and clearing out carbon dioxide. Pneumonia wreaks havoc on this exchange system.

每次呼吸时，空气都会顺着气管，通过一系列通道，然后到达肺部的小气囊群。这些小气囊促进了关键的交换：让我们呼吸的空气中的氧气进入血液，并清除二氧化碳。肺炎对这一交换系统造成了严重破坏。

https://www.bilibili.com/video/BV19V411a7yF?from=search&seid=4589821611097293044