大量的潮湿木材周围河岸，加上很多事情要使用的火种。

Lots of damp wood around the river Banks, plus lots of things to use for tinder.

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木材在潮湿的时候就会膨胀，而干燥的时候会缩小，这取决于其中含有的氢氧基团，它可以吸收和释放水分。

Timber swells when it is damp and shrinks when it is dry because it contains groups of atoms called hydroxyl groups, which absorb and release water.

youdao

木材潮湿后往往会膨胀。

Wood often swells when wet.

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