copper (chemistry) / see also 紅銅|红铜[hong2 tong2] / CL:塊|块[kuai4]
铜
=
同
+
钅
:
Tommy Turtle (tu) runs a copper (铜) mine in the engine's kitchen ((e)ng2). He managed to force two twins (同) to work for him and mine the copper using golden harpoons (钅).
锈
=
钅
+
秀
:
Marie Curie (xi) is demonstrating in a talent show (秀) in the outhouse's bathroom (ou4) how she can magically remove the rust (锈) from a golden harpoon (钅) by dipping it in the toilet. Her secret is that she poured the right chemicals in the toilet earlier.