2 Oxygen is essential for life : if a person enters an oxygen deficient atmosphere he/she could collapse immediately and die if not rescued.
2 Oxygen is essential for life : if a person enters an oxygen deficient atmosphere he/she could collapse immediately and die if not rescued.
氧是生命的基本元素，如果人进入缺氧的地方，他/她会立即昏迷，如果不及时救治，就会死亡。