That they are dry and not wet climates
Trisomy=3 chromosomes; 1 more than the required pair (2)
21=the type of chromosome
So, here we can eliminate A and B.
Now we have C and D.
I know that when sperm cell(s) simultaneously fertilize [an] egg, a class of identical twins will form. Therefore, we can eliminate D, leaving us with merely C. Henceforth, C is your final answer.
There has to be one side with a high concentration and another side with a lower concentration
Answer:
A maple tree is an example of a tree