nitrogen

n. /ˈnaɪ.trə.dʒən/ B2

氮；氮气

A colourless gas that forms about seventy-eight percent of the earth's atmosphere.

仙境例句

The old Tortoise taught that most of the air is nitrogen, which nobody can see.

老陆龟教大家：空气里大部分是氮气，谁也看不见它。