Indentify each stage on the diagram with the name of the stage? PLEASE HELP

1.black dwarf

H.white dwarf

A.Red giant

B.Main sequence

C.Nebula

D.Stellar nursey

Explanation:

On the last part where the main sequence happens, it really depends on the mass of the star using the sun as an example, our sun has a low mass meaning when it close to its dying form it would go to Planetary Nebula then collaspe as a white dwarf. When a massive star goes through the main sequence and it reaches its dying form, with the high mass it'll also die as a white drawf when it has very high mass it'll possibly end up as a black hole.

Hope this helps, sorry if it doesn't!

a and b

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.