biological oxygen

例句：

1. 1. The study of biology is essentialfor understanding the world around us.
   研究生物学对于我们理解周围的世界至关重要。
2. 2. Thebiological oxygen demand (BOD) is a measure ofhow much oxygen a body needs tosurvive.
   生物需氧量是衡量一个生物体需要多少氧气来生存的一个指标。
3. 3. In order to maintain healthy lungs, it's important to breathe infresh air and avoid breathing in pollutedair.
   为了保持肺部健康，呼吸新鲜空气并避免吸入污染的空气是很重要的。