crust of iron的用法和樣例：
例句
- Leaching of arsenic from arsenic and iron slag obtained from cobalt metallurgy with sodium hydroxide has been studied.
研究了用氫氧化鈉浸出鈷冶金過程中產出的高砷鐵渣中的砷。 - The best presidents are like magnets below a piece of paper, invisibly aligning iron filings into a new pattern of their making.
最好的總統，就像放在紙下面的一塊磁鐵，雖然看不見，但會吸引鐵渣形成新的圖案。
