dross

他在整理笔记时去除了所有无用的内容。

He removed all the ___dross when organizing his notes.

冶炼工用长柄勺从熔铜表面撇去了浮渣。

The smelter used a long-handled ladle to skim the ___dross from the surface of the molten copper.

在筛选了几个小时的投稿后，这位文学代理得出结论——那堆稿件中大多数都是垃圾。

After hours of sifting through submissions, the literary agent concluded that most of the pile was ___dross.