Which is the best conclusion to draw about the Columbian Exchange?

How does the existence of a site like catus hill demonstrate the challenge that archaeologist face when making theories?

Why are slanted roofs found on many buildings within russia and finland? a. to prevent ice slides. b. to prevent the build-up of water during heavy rains. c. to prevent heat from escaping during the clod winter months. d. to prevent snow build-up.

According to article 1, why did massachusetts raise their taxes on citizens, and what about the currency of the time made it difficult for citizens to pay these taxes