question: pen:ink
choices.label: A B C D
choices.text: blood vessels:blood coal stove:coal ash electric drill:drill bit pistol:bullet
explanation: "ink" needs to be filled in a "pen" for usage. "ink" is a consumable. the carrier of "blood" is the "blood vessel", "blood" is not consumable. the product of coal consumption by the "coal stove" is "coal ash". the "drill bit" needs to be installed on an "electric drill" to use it, but the "drill bit" is not a consumable. "bullets" need to be loaded into "pistols" to be used, and "bullets" are consumables.
relation: pen ink R3.10