Which of the following is a way in which earth material is returned to the surface? a. a volcanic eruption b. melting from pressure and heat c. weathering and erosion d. deposition

amber has allowed scientists to study dna that has been preserved over millions of years.

but there is no

i guess you forgot putting it.

not sure if this is what you'r looking for nnew= nold

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.