<span>The correct answer for the question that is being presented above is this one: "D. Tundra." This ecosystem is common in eastern and northern Siberia. Flora include mosses, summer flowers, and small shrubs. Animals include wolves, reindeer, foxes, and rabbits. The ecosystems that is described in the paragraph above is the tundra.</span>
C. Fishing
I think fishing would make sense due to living in a river valley.
The line located at 0° latitude is the equator.
I would like to refer you to this website, it has everything you are asking about--
http://thediplomat.com/2015/01/china-the-influence-of-history/
Hope this helps!