In the lungs, the capillary lines up alongside a small sack of air called an alveolus.

在肺里，毛细血管包绕着半球状囊泡，即肺泡。

In the organs, the red blood cells line up alongside tissue cells and drop off oxygen, as well as pick up carbon dioxide basically the reverse of what happens with the alveolus in the lung.

在器官中，红细胞与组织细胞排列在一起，并释放氧气，同时吸收二氧化碳；基本上与血液在肺泡处的情况相反。