这个清洁设备采用四阶段过滤系统，确保空气高度纯净。

This cleaning device uses a ___four-stage filtration system to ensure highly purified air.

这台洗衣机采用四阶段清洗程序，确保衣物彻底清洁。

This washing machine uses a ___four-stage cleaning process to ensure thorough garment cleaning.