Which behaviors are most likely to be prohibited in a safety contract?

talking during the lab

modifying the lab procedure without the teacher's permission

leaving active heat sources unattended

calling 911 during an emergency

using laboratory chemicals for practical jokes or tricks

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.