他是这座古建筑的主要保护者，致力于修复和维护工作。

He is the chief ___preserver of this ancient building, dedicated to its restoration and maintenance.

这种罐头食品不含任何人工防腐剂。

This canned food doesn't contain any artificial ___preservatives.

游泳时孩子们都穿着救生衣以防万一。

The kids all wore ___preservers while swimming just in case.