The sun will never burn out

· But in about 5 billion years, the sun will run out of ... For about a billion years, the sun will burn as a red giant and whole universe will be destroyed

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.

because the light is a great source of energy for the plants to survive. (i hope this )