question: windows:curtains
choices.label: A B C D
choices.text: pencil:eraser coffee:milk tea hair:comb building:steel
explanation: "curtains" are installed on the "windows" . "pencil" and "eraser" are both types of stationery. "coffee" and "milk tea" are both types of beverages. "combs" are used on "hair". the raw material of "building" is "steel".
relation: windows curtains R3.10
relation: pencil eraser R2.4
relation: coffee milk tea R2.4
relation: hair comb R3.10
relation: building steel R3.7