13. The geological theory that states that pieces of Earth's outer layer are in constant, slow motion is the theoryof *
subduction.
plate tectonics.
sea-floor spreading
deep-ocean trenches.

just finished the test, the answer is d, greg is the least cost-effective because he charges the most for the project

a. population growth is decreasing

-2

+4

-10

-3

-8

-3

so the population decreased by 24 because 3+3+8+10+2=26-2=24.

hoped i !

explanation:

answerwestern plateau,     central lowlands,     great dividing range;