填空题

In Norway and Sweden, the process called______has been used extensively to "cancel out" the acidity in acidic lakes.

【参考答案】

liming

<上一题目录下一题>

热门试题

填空题

Among the alternative energy sources,______, and coal are the cheapest forms today.

填空题

The two pollutants that cause acid deposition are______and nitrogen oxides (NOx).