question: gunpowder:fireworks
choices.label: A B C D
choices.text: gasoline:car metal:compass radio:mobile phone glass:magnifying glass
explanation: "gunpowder" is a necessary raw material for making "fireworks", and "fireworks" cannot be made from materials other than "gunpowder". "gasoline" is the power source of the "car", besides "gasoline", "car" has other power sources . the pointer of the "compass" must be a "metal" magnetic needle, and "metal" is the necessary raw material for making a "compass" "radio" is the basic technology for the "mobile phone" to make calls, "radio" is not a necessary raw material for making a "mobile phone" "glass" is the raw material for making "magnifying glass", but the new "magnifying glass" lens can be made of water, resin, rare ores and other materials, "glass" is not a necessary raw material for making "magnifying glass"
relation: gunpowder fireworks R3.7
relation: metal compass R3.7
relation: radio mobile phone R3.10