越硬的物料制砂起来越困难，而且对设备的磨损越严重。

The more hard material made up more difficult, and sand on equipment wear the more serious.

youdao

越硬的物料制砂起来越困难，而且对设备的磨损越严重。

The more hard material made up more difficult, and sand on equipment wear the more serious.

youdao