Treatment with acid before analysis.

分析前先用酸进行的处理。

Concentrations of the acid tend to decrease stepwise.

酸的浓度会逐渐降低。

Various species of diatoms display different tolerances to acid.

不同种类的硅藻对酸表现出不同的耐受力。

Trees are dying from acid rain.

树木因为酸雨而奄奄一息。

Acid fallout from power stations.

发电站飘来的酸性浮尘。