为了防止标本腐烂，科学家使用了特殊的固定剂。

Scientists used a special ___fixative to prevent the specimen from decaying.

显微镜检查前需要用固定剂处理组织样本。

A ___fixative is needed to preserve tissue samples before microscopic examination.

这款香水添加了一种特殊的定香剂，能让香味持续一整天。

This perfume uses a special ___fixative to make the fragrance last all day.