gas exchange
respiratory system
alveolar sacs
lung function
A: How do we breathe oxygen into our blood?
A：我们是如何把氧气吸入血液的？
B: It happens through the tiny alveoli in our lungs.
B：它是通过我们肺部微小的肺泡完成的。
1) 肺部微小气囊
2) 气体交换场所
3) 呼吸系统的末端结构
1. 肺泡
noun
1. tiny air sacs in the lungs where gas exchange occurs