使用劣质材料会降低产品的整体价值。

Using low-quality materials ___debases the overall value of the product.

散布谣言只会降低公众讨论的品质。

Spreading rumors only ___debases the quality of public discussion.

一些不诚实的商人通过掺杂廉价原料来降低银的纯度。

Some dishonest merchants ___debase silver by mixing it with cheaper materials.