Two men in belt harnesses are working on a construction project , though only one wears his hard hat .
It is probably the case that two construction workers are building something , one is risking a head injury .
It is probably the case that two construction workers are building something , one is risking a head injury .
We doubt that two construction workers are building something , one is risking a head injury .
Two construction workers are building something , one is risking a head injury .