A common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume,a constituent of all living tissues.

• 一种常见的非金属元素，通常为无色无嗅无味的惰性二原子气体，体积占大气的78%25，活细胞的组成成分。