1. The disadvantages are mainly high equipment costs and plugging of the lines by sediment, salt encrustation, or algae. 缺点主要是设备费用高，管道易被泥沙、盐分结晶或藻类植物堵塞。
2. In rough-set theoretic sense, the histogram correlates with the lower approximation and encrustation of histogram correlates with upper approximation. 从粗糙集理论意义上来说，直方图的外层与上近似有关，而直方图取值与下近似有关。
3. "German water doctor" just coil wrapped around a water pipe, not contact with water, but they will make to remove the encrustation, That furring to where? “德国水大夫”只是把线圈缠在水管外，并未与水接触，但却把水垢除掉了，那水垢去哪儿了？
英英解释
n.
1. the formation of a crust
2. a hard outer layer that covers something
3. a decorative coating of contrasting material that is applied to a surface as an inlay or overlay
