harmful substance

• 有害物质

harmful substance的用法和样例：

例句

1. They were trying to remove harmful substances from the soil.
   他们正设法去除土壤里的有害物质。
2. It can effectively improve air quality by releasing the fresh air to purify the indoor air and adsorb harmful substance.
   排放清新空气以净化室内空气，吸附有害物质，有效地提高空气质量。