1. 酸雨：acid potassium sulfate 硫酸氢钾 | acid precipitation 酸雨 | acid proof alloy 耐酸合金

2. 酸性降水：acid number 酸值 | acid precipitation 酸性降水 | acid radical 酸根

3. 酸沉降：预析出:pre-precipitation | 酸沉降:acid precipitation | 大气降雨:precipitation

4. 改进酸析：混凝沉淀:chemical precipitation | 改进酸析:acid precipitation | 降雨过程:precipitation process

noun

1. rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water

    Synonym: acid rain