Question: You are looking at a grand historical structure featuring large pointed arches, a high ceiling supported by ribbed vaults, and external stone supports called flying buttresses that allow for very tall stained-glass windows. Which specific historical era and architectural style does this structure likely belong to?

Question: An archaeologist uncovers the foundations of two separate historical bridges. Bridge A has massive, thick piers made of unreinforced stone blocks and features semi-circular (round) arches. Bridge B has incredibly thin, lattice-like piers and very long, flat spans made of a dark, rusting metal. Based on the history of civil engineering materials, which historical eras do these bridges most likely belong to, and why?