translation.en: White blood cells are our body's defense against bacterial invaders, and when they sense this inflammation due to infection, they will enter from the blood into the lung and engulf the bacteria.
translation.zh: 白细胞是人类身体的防御者 专门针对细菌入侵者， 当白细胞感觉到这种炎症感染， 它们将从血液进入肺 并吞噬细菌。