One of the sailors' hobbies (except rubbing the deck) is to polish brass doorplates. That's why they shine so well. However, half of the inscriptions can hardly be read.
Such materials can be used in lubricating bearings, diamond tools and rubbing tools, as substitution for copper powder, bronze powder and brass powder, thus reducing the production costs considerably.
可代替一些铜粉、青铜粉和黄铜粉产品,从原料上大大降低了生产成本。
释义
n.
the action of rubbing heelball or chalk over paper laid on an engraved brass to reproduce its design