英语语法分析

Cattle manure and calcium superphosphate were main polluting material.

牛粪、过钙是基质中主要镉污染物质。

We make superphosphate by reacting rock phosphate with sulphuric acid.

我们使磷酸盐岩同硫酸发生化学反应制造过磷酸钙。

It is practically insoluble in water and only very slowly soluble in diluted acids, so it is largely converted for fertilizing purposes into superphosphate.

磷酸三钙几乎完全不溶于水，在稀酸中溶解也极为缓慢。所以，作为肥料，通常得把磷酸三钙转化为过磷酸钙。