Which one of the following criteria is necessary for natural selection to occur? a. individuals show no variation in fitness levels. b. individuals have the same adaptations. c. a struggle for existence is apparent. d. enough resources exist for individuals to survive and thrive.

How many years would it take the atlantic ocean to grow 500 centimeters? show your work.

Which locations on the map are low-pressure areas? a b c d e

1. seamount a raised footwall block between normal fault creates this 2. syncline break between rocks where a hanging wall rises relative to a footwall 3. hot spring on rolling hills, this a dip between hills 4. volcanic neck created when a block with hanging walls slips down between normal faults 5. caldera underwater volcano that never reaches above sea level 6. horst natural hot water on earth's surface containing many minerals 7. graben underwater volcano whose top is eroded flat by waves 8. crater less than a mile in diameter; looks like a bowl at the top of a volcano 9. guyot magma that filled the central vent that remains after the volcano has eroded 10. reverse fault over 1 mile in diameter; looks like a bowl over a volcano