A " lode, " then, is a large amount of metal ore that is found in a certain area.

那么， “矿脉”就是在某个地区发现的大量金属矿石。

A " filing" is a small amount of metal that is put into this little hole – this cavity – to cover and protect the teeth so that they are not damaged further.

“锉刀”是将少量金属放入这个小孔 - 这个空腔 - 以覆盖和保护牙齿，以免它们进一步受损。