Mountain climbers often carry oxygen tanks because the air is very thin at high altitudes.

登山者通常会携带氧气筒，因为在极高的地带空气相当稀薄。

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Mountain climbers often carry oxygen tanks because the air is very thin at high altitudes.

登山者通常会携带氧气筒，因为在极高的地带空气相当稀薄。

youdao