HELP me this is for Honors Biology!!

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

What is the correct answer for the process of water eroding soil? rills, sheet erosion, gullies sheet erosion, rill, gullies gullies, rills, sheet erosion sheet erosion, gullies, rills

Abiologist counts the number of rabbits in a population each year and observes a decrease in population. since the coyote population has exploded, the biologist concludes that the coyote population has had a negative interaction with the rabbit population. which describes the biologist’s actions? a.) experimentationb.) inferencec.) observationd.) interacting