There must be an internal cause for this change.

这个变化肯定有内因。

youdao

This is an internal cause of overall spirit and overall design of a country or the legal culture of nationality.

这是一个国家或民族法律文化的总体精神和总体样式的内因。

youdao

Unlike hernias in men, which are far more common, those that afflict women are usually small and internal and rarely cause an obvious bulge.

和人们熟悉男性疝气不同，女性疝气通常体积较小，位于腹内，很少出现明显的突起。

youdao

An internal inquiry into the cause of the sinking is under way.

BBC: Yellow Duckmarine sinks in Albert Dock in Liverpool

It is for this reason that, while the Greek CP wants out of the euro, the growingly influential far left parliamentary group SYRIZA does not, and neither does the hard-right religious party LAOS. Everybody can see that an external devaluation will be chaotic, painful and cause its own kind of social unrest, just as the attempted internal devaluation is doing.

BBC: Greek referendum is coin-flip on euro exit