[reema.rifkhan]

The hydrogen in C₄, C₆, C₁₀ and C₈ belong to same hydrogen environment.
the hydrogen in C₃, C₁, C₁₁ and C₁₃ belong to the another hydrogen environment.
and hydrogen in C₁₂ and C₂ belong to the once again, another hydrogen environment.
My question is C₃, C₁ , C₁₁  C₁₃, C₁₂ and C₂ all have two hydrogen in the neighboring carbon atoms.
So why aren't they classified as one hydrogen environment?
 Instead why are the categorized under two different environments?
Answer needed as soon as possible please. Thanks in advance!

[Babcock_Hall]

Try drawing minor resonance structures, and don't be afraid to put positive or negative charges on certain atoms.  Let's see what you come up with.

[Babcock_Hall]

Try putting three electron pairs on oxygen (which will carry a formal charge of minus one), and see where the positive charge goes.