Stomach acid has a pH of about . a. 4 c. 6 b. 2 d. 10

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .