purl knit是什么意思

用法例句

Single or double reverse flotation technology was used to separate phosphate rock with high content of magnesium and low silicon.

正-反浮选工艺适合处理海口高硅高镁的磷块矿石,低硅高镁的磷块岩的适宜选矿工艺为单一或双反浮选。