impurity penetration

例句：

1. 1.The contamination of the water source by impurities poses a significant threat to public health.
   水源受到杂质的污染对公众健康构成严重威胁。
2. 2.The process of purification is critical for preventing impurity penetration in the production line.
   净化过程对于防止生产线中的杂质渗透至关重要。
3. 3. The research on impurity penetration has been a hot topic in recent years.
   近年来，关于杂质渗透的研究成为了一个热门话题。