question: product of labor:commodity:high quality and low price
choices.label: A B C D
choices.text: orchid:plant:pleasant aroma metal:copper:conductivity natural gas:methane:combustion animals:mammals:burrowing
explanation: "Commodity" is a kind of "labor product". Some "commodities" have the characteristics of "good quality and low price". "orchid" is a kind of "plant", but the word order is inconsistent with the query. "copper" is a kind of "metal", and "conductivity" is a property of "copper". "methane" is a component of "natural gas". "mammals" belong to "animals", and some "mammals" have the nature of "burrowing".
relation: product of labor commodity R2.2
relation: high quality and low price commodity R3.1
relation: orchid plant R2.2
relation: copper metal R2.2
relation: conductivity copper R3.1
relation: natural gas methane R2.3
relation: animals mammals R2.2
relation: burrowing mammals R3.2