酸性降水；
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