From long time ago, because of reasons such as high mining cost, there are many limitations for the development of domestic ore mining.

一直以来，我国国产矿石因为开采成本大等原因，其开发一直受到制约。

youdao

From long time ago, because of reasons such as high mining cost, there are many limitations for the development of domestic ore mining.

一直以来，我国国产矿石因为开采成本大等原因，其开发一直受到制约。

youdao