Which of the following explains why the mucus plug is released before birth? It allows the amniotic sac to break.

It initiates uterine contractions.

It allows the cervix to fully dilate.

It is no longer needed to block the cervix.

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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.