piliferous layer

例句：

1. 1. The study found a significant increase in the number of piliferous layers in the area.
   研究发现该地区的富集层数量显著增加。
2. 2. The researchers discovered that the piliferous layer was responsible for the unusually high levels of pollutants in the water.
   研究人员发现富集层是导致水中异常高浓度污染物的原因。
3. 3. The piliferous layer is an important indicator of environmental health, and its depletion could have serious consequences.
   富集层是环境健康的重要指标，其减少可能会产生严重后果。