question: object:inertia
choices.label: A B C D
choices.text: observation:objectivity liquid:fluidity precious metals:magnetic gas:stability
explanation: "objects" must have "inertia". "observation" is a purposeful and planned perceptual activity and an advanced form of perception. "objectivity" is the basic requirement of "observation", but "objectivity" is not an inevitable requirement of "observation". "liquid" must have "fluidity". a "precious metal" may be "magnetic". a "precious metal" may not be "magnetic". "gas" has no "stability".
relation: inertia object R3.1
relation: fluidity liquid R3.1
relation: precious metals magnetic R3.2
relation: stability gas R3.1