Which of the following is true concerning continental crust?
a. it does not contain radioactive elements.
b. it mostly contains heavier and denser minerals than the mantle.
c. it efficiently transfers heat from the mantle to the surface.
d. none of the above

Which of the following is true about fossils? a. the relative age of fossils cannot be determined from their position in sedimentary layers. b. fossils found in lower layers of sedimentary rock are as old as fossils found in upper layers of sedimentary rock. c. fossils found in upper layers of sedimentary rock are older than fossils found in lower layers of sedimentary rock. d. fossils found in lower layers of sedimentary rock are older than fossils found in upper layers of sedimentary rock.

The coco river is a natural border between nicaragua and which other country

Wegeners theory of continental drift states that the continents have changed throughout history while the theory of plate tectonics