What are the sub regions of south america

The covers all of earth like a thin shell, but it is not a solid sheet of material. it is broken up into several large sections and many smaller ones. fill in the blank.

Which layer surrounds the center of the earth? a: crust b: core c: mantle

Will give brainliest asaap plz im in a major hurry to finish which of these pairs of objects exerts the greatest gravitational force on each other? object 1 and object 3 object 4 and object 3 object 1 and object 4 object 4 and object 2