internal causation

• 内在原因

internal causation的用法和样例：

例句

1. This research finds out the occurrence of ferric oxide,and sets forth the internal cause of difficult-to removing iron for improvement of whiteness of the illite ores.
   本研究查清了氧化铁的赋存形式，阐述了伊利石难以除铁增白的内在原因。