What is used for safety, but is not safe?

What did europeans build much of during the eleventh and twelfth centuries? ?

What is one way the spanish war of independence encouraged those in the colonies to seek new political and economic rights? colonies took advantage of spain’s weakened ability to prevent rebellion. the disruptions caused by the war encouraged colonial merchants to seek markets in the pacific. the exposure to french ideas through the war convinced many in spain to provide these liberties to the colonies. the war with france made spain tighten their political and economic hold on the colonies in desperation.

Which piece of information would most a historian create an interpretation of this photograph of works in a factory?