氮气 (dàn qì) — nitrogen (chemical element N₂)

定義

例文

• 空气中大部分是氮气。
  Kōng qì zhōng dà bù fen shì dàn qì.
  Most of the air is nitrogen.
• 焊接时要用氮气保护金属。
  Hàn jiē shí yào yòng dàn qì bǎo hù jīn shǔ.
  When welding, you need to use nitrogen to protect the metal.
• 食品包装里常充入氮气来保鲜。
  Shí pǐn bāo zhuāng lǐ cháng chōng rù dàn qì lái bǎo xiān.
  Food packaging is often filled with nitrogen to keep it fresh.