What holds the two strands of a dna molecule together?

weak hydrogen bonds

hope that's right :)

yes its like the dead sea which is full of salt which makes you stay afloat

so yes an egg will float in salt

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.