title: Plough
context: A plough (UK) or plow (US; both /plaʊ/) is a tool or farm implement used in farming for initial cultivation of soil in preparation for sowing seed or planting to loosen or turn the soil.[1] Ploughs were traditionally drawn by working animals such as oxen and horses, but in modern times are mostly drawn by tractors. A plough may be made of wood, iron, or steel frame with an attached blade or stick used to cut the soil and loosen it. It has been a basic instrument for most of recorded history, although despite archeological evidence for its use[2] written references to the plough do not appear in the English language before c. 1100, after which point it is referenced frequently. The plough represents one of the major agricultural inventions in human history. The earliest ploughs were wheelless, and the Romans used a wheelless plough called the aratrum, but Celtic peoples began using wheeled ploughs during the Roman era.[3]
question: What are the most common materials used for making a plow?
answers.text: wood, iron, or steel frame wood, iron, or steel