Input question: In 1946, what useful gadget was invented by Percy Spencer?

Output answer: microwave oven

Input question: Who was Henry the Eighth's sixth wife?

Output answer: katherine parr

Input question: By which two words is the chemical compound with the formula NH4NO3 known?

Output answer: ammonium nitrate

Input question: Where would one find the Appleton layer?

Output answer:
earth s upper atmosphere