Lexical choice – metalwork action verb: complete the sentence with the verb commonly used for striking metal with a tool in a marketplace context. Sentence: "A crescendo of metallic thuds arose from the market, where the iron-smiths were ____ the pieces of metals." Select the most idiomatic verb.

Given data

• Context: blacksmiths/iron-smiths generating metallic thuds while working pieces of metal.
• Options: flattening, striking, hammering, thrashing.

Concept/Approach
The standard verb for shaping metal with repeated blows using a hammer is hammering. It naturally explains the "crescendo of metallic thuds".

Option analysis
hammering — precise technical and everyday term for repeated hammer blows in metalwork. ✅flattening — a possible result of hammering/rolling, but not the direct action causing thuds.striking — generic; lacks the specific metalworking nuance and is less idiomatic here.thrashing — connotes violent beating (often of people/crops/clothes), not appropriate for metal shaping.

Usage note
Typical collocation: hammering (hot) metal, hammering out shapes.

Final Answer
hammering