医生让病人吸一点儿氧气，帮助他恢复呼吸。

Yīshēng ràng bìngrén xī yìdiǎnr yǎngqì, bāngzhù tā huīfù hūxī.

The doctor let the patient inhale some oxygen to help him recover his breathing.

在高海拔地区，空气中的氧气含量比较低。

Zài gāo hǎibá dìqū, kōngqì zhōng de yǎngqì hánliàng bǐjiào dī.

In high-altitude areas, the oxygen content in the air is relatively low.