I simply just do not understand this it is confusing and it is my last question so if you could help me that would be really awesome.

a=5

b=9

c=3

d=4

Explanation:

A=5, B=9, C=3, D=4

Explanation:

For example 3+1 = 4 and it also shows that D = 1+3. It could get confusing if you try and connect the columns with rows and make a double digit sum when you should only focus on one column or row and not mix them up making the wrong result. For example starting from the number 2 in the top row (3+2=A) and add number 1 to the is where one could mess up the puzzle when it should be 3+2 = A only. And that’s how it’s done. Good luck!

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.

b. 20: 5

explanation:

20% of the worlds population lives in southwest asia, and less than 5% of the world's

land area.