Input question: What was the tallest man-made structure before the completion of the Eiffel Tower?

Output answer: washington monument

Input question: Which fuel is commonly found in cigarette lighters?

Output answer: butane

Input question: What is the name of the sharp-toothed wheel inserted into the end of a spur?

Output answer: rowel

Input question: In 'Scrabble', how many 'D' tiles are there?

Output answer:
four