农民们在使用磷化氢熏蒸粮食仓库时，必须佩戴防护装备。

Farmers must wear protective gear when using ___phosphine to fumigate grain storage.

研究人员开发了一种新型磷化氢衍生物用于农业杀虫剂。

Scientists developed a new ___phosphine derivative for agricultural pesticides.