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材料: 乒乓球、金属汤匙、木板(或塑料垫板)、塑料笔杆。我的问题: 我脱毛衣时听到轻微的“噼啪”声,在黑暗中还能看见电火花,这是为什么呢?
Materials: table tennis, metal spoons, wood (or plastic plate), plastic pen holder. My question: I heard a slight “crackling” sound when I took off my sweater, and I saw electric sparks in the dark. Why is this?