question: selfie:photography
choices.label: A B C D
choices.text: iron ore:metal teahouse:place wechat:blog cabin:spaceship
explanation: "selfie" is a type of "photography". "iron ore" is a rock or sediment containing compounds from which iron can be extracted. "iron ore" is not "metal", and iron is "metal". "teahouse" is a kind of "place". both "wechat" and "blog" belong to the same category of social communication tools. a "cabin" is part of a "spaceship".
relation: selfie photography R2.2
relation: teahouse place R2.2
relation: wechat blog R2.4
relation: cabin spaceship R2.3