研究发现，某些烟草制品中含有亚硝胺，这种物质可能致癌。

Studies found that certain tobacco products contain ___nitrosamines, which are potentially cancer-causing compounds.

加工肉类中可能含有亚硝胺，这是一种潜在的致癌物质。

Processed meats may contain ___nitrosamines, which are potential carcinogens.