Twelve days of Christmas lyrics

There are traits like blood type and eye color, and others like speaking english or having a scar. what are the terms used to describe these different types of traits? how are each defined?

How many soultions does the system of equations have y= -6x + 330x + 5y = 15a.one b.twoc.infinity manyd.none

Which of these cities would be found in the most densely populated area on northern section of the map? a) beijing b) seoul c) shanghai d) tokyo