| 释义 |
O2
释义
symb. 氧气 (Oxygen, Dioxygen)
例句
1·A backpack sends O2 in to let astronauts breathe normally.
一个背包可以输送氧气，让宇航员正常呼吸。
2·A large tree might make around 100kg of O2 per year.
一棵大树每年可以产生大约100公斤的氧气。
3·It takes about 7 to 8 trees to make enough O2 for one person to breathe for a year.
大约需要7到8棵树产生足够一个人呼吸一年的氧气。
同义词
n.
氧
oxygen
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