Answer:
I am pretty sure that I know what Anna is working on, given that she wants to find the patterns of demographic variation, is population structure. This structure deals with variations in age, gender, and other qualities of a population, and I believe that is what she wants to find out. So the answer to your question would be that population structures are the patterns of demographic variation.
Explanation:
potential energy is the correct answer
The formula of this is : MV = MV or Molarity × Volume = Molarity × Volume. So you do:
25X = 18×.205=.1476M
