Why did early civilization arise in the valleys of the tigris and euphrates rivers ?

The primary agent of contact metamorphism is

What are the answers for the following questions?

Compare the quantity in column a with the quantity in column b. pa p a is tangent to the circle at a. column a column b ap a p ax a x question 4 options: the two quantities are equal. the quantity in column a is greater. the relationship cannot be determined from the information given. the quantity in column b is greater.