Exit Which of the following is NOT a source of Earth's internal heat?

a. mantle convection

b. radioactive substances

c. gravitational contraction

d. past bombardment by asteroids

Which of the following statements about the urbanization of early civilizations is true? A. Early civilizations tended to take two main forms: nomadic tent dwellers and semi-nomadic herders, both of which existed in the desert and semiarid regions.

Describe what is meant by texture in terms of a sedimentary rocks.

Why do volcanoes take on different shapes at earth's surface?

How long is a "revolution"?

What is the difference between a cobble-sized piece of colluvium found on slopes and a cobble-sized piece of alluvium found along river beds?

What qualities did greek architects strive for in their work

What is the difference between density and distribution

What structure is present in dolphin but absent or greatly reduced in other whales?

Which type of rock was precipitated from seawater as the mediterranean sea evaported between 8 million years ago and 5.5 million years ago

Why is climate change a big problem?