在制作蛋糕前，她用一个筛子把糖粉过筛得更细腻。

Before making the cake, she used a ___sifter to make the powdered sugar finer.

海关官员充当着严格的筛选者，仔细检查每一件入境物品。

The customs officer serves as a strict ___sifter, carefully inspecting every item entering the country.