Weigh the risks and rewards of space flight by explaining why you would or would not like to be a passenger on the Space Shuttle.

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.

b is the answer and if you need further with anything message me