Answer:
The trade in beaver pelts had been the centre of Canada's economy from the early 17th century to the early 19th century. Based on the history, the beaver is the national symbol of Canada.
Explanation:
Corbel dome: arch like construction method to span a space or void in a structure such as a entryway.
Tholos: Beehive like tomb; Burial structure made out of mud bricks and stones.
Rotunda: Round building or dome.