passive film

例句：

1. 1. The passive film formed on the surface of the metal is insulating.
   金属表面形成的被动膜是绝缘的。
2. 2.The researchers found that the passive film could be used to protect the surface from corrosion.
   研究人员发现，被动膜可以用来保护表面免受腐蚀。
3. 3. The passive film was responsible for the low electrical resistance of the material.
   被动膜导致了材料的低电阻性。