The asphalt mostly through the natural evaporation and oxidation, generally do not contain any poison.

这种沥青大都经过天然蒸发、氧化，一般已不含有任何毒素。

youdao

The asphalt mostly through the natural evaporation and oxidation, generally do not contain any poison.

这种沥青大都经过天然蒸发、氧化，一般已不含有任何毒素。

youdao