asap !
question 19 (3 points)

what does the theory of uniformitarianism state?
question 19 options:

earth has not changed for billions of years.

evidence from fossils can give us glimpses into the past.

geologic processes we see today were also at work in the past.

major catastrophic events shaped the earth.
question 20 (3 points)

why are radioactive substances useful for measuring geologic time?
question 20 options:

radioactive substances are stable and do not change.

samples of radioactive substances are easy to collect from rocks.

half-lives of radioactive substances are short.

radioactive substances undergo decay at a predictable rate.
question 21 (3 points)

an unconformity is found in a geologic cross section. what does this indicate happened in this area?
question 21 options:

an earthquake occurred along a fault line.

new sediment was deposited.

tectonic forces deformed the rock.

wind and rain caused erosion.
question 22 (3 points)

the precambrian eon is separated from the phanerozoic eon in the fossil record because of
question 22 options:

the appearance and disappearance of volcanoes.

the sudden appearance of organisms.

the number of earthquakes occurring at that time.

the creation of new ocean ridges.