甲醛是一种常见的醛类化合物，常用于防腐剂中。

Formaldehyde is a common ___aldehyde often used in preservatives.

这种香水中独特的玫瑰香味源自一种特殊的醛类化合物。

The distinctive rose fragrance in this perfume comes from a special type of ___aldehyde.

在酒精代谢过程中，乙醛是一种重要的中间产物。

In alcohol metabolism, ___aldehyde is an important intermediate product.