primary oxygen

• 主系统用氧

primary oxygen的用法和样例：

例句

1. Oxygen bome calorimeter was used to determine calorific value of vinasse.
   用氧弹直接测定糖厂废醪液的发热量。
2. As the atmosphere slowly became rich in oxygen, life changed to take advantage of oxygen as a source of energy.
   随着大气中氧慢慢地增多，生命也就变得喜欢用氧作为自己的能源。