Abstract:
  -First sentence is very long....sperate into two or condence the
   verbosity. 
  
--I prefer to keep it this way.
        
  -"ii) Both starbursting ... POWERED BY ACCRETION POWERED..."
    awkward, you don't need powered twice...how about "powered by an
    accretion disk"  or "nuclei which contain accretion-powered disks" 
    
--Fixed 

Introduction:
  - Last sentence: "The goal of this...for luminous/ultraluminous
    galaxies and ..".
    luminous or ultraluminous (IR galaxies?) You haven't defined
    these terms yet.
    
--Fixed

Section 3.3:
  - Second to last sentence...just curious if you used any aperture
  corrections for comparing the 24mu images with the SH FOVs...since
  the resolution is not matched (I think)
  
--The apertures are 3-4 times the size of the 24um PSF, so not a concern

Section 4.3:
  -5th Sentence:  "The long-dashed curves..."
   Why are the empirical fitted lines of Keweley and Kauffman
   different if they both used hundreds to thousands of galaxies
   (where there difference in their selection techniques?) One
   sentence here clarifying this would be useful.
   
--This has been improved

  -7th Sentence: The footnote is pretty important...Thought you may
   want bring it up to the main text (unless you are hiding it on
   purpose),

--This has all been updated

  -8th (last) Sentence: "For the purposes of the remainder of this
   study..."  Just sounds a little awkward, maybe a rewrite here would
   be good, or just remove 'the purposes" and say "For the remainder
   of this study"
   
--Changed

Section 4.4:
  -The first sentence seems a little funny due to the semi-colon.  If
  you want to keep it, how about "...54.9eV; consequently, photons at
  least this energetic..."
  
--Done

  -Second sentence:  This is really not too big of a deal, but you
   first mention excitation potential (EP) for [OIV] and then in this
   sentence refer to the ionization potential (IP) for [NeI]...maybe
   stay consistent for the reader?
   
--I've now made these all consistent

  -3rd Sentence: "Compared to 21.6eV photons, 54.9eV photons are far
   more likely to stem from accretion-powered disks (RATHER?) than
   star formation..."  Why?  I think either giving a reference or
   mentioning the average radiation field strength of each would be
   good to back up this statement.
   
--Reference added

  -Paragraph 4, Sentence 2: "The 100% AGN anchor..."
   Where do these numbers come from?  I had no idea when going through
   this paragraph how you came to the realization that such ratios and
   EWs corresponded to pure AGN and SF...did you just take them from
   object for which we know they are being powered by pure AGN and SF
   processes?  Also, anchor is kind of colloquial, maybe use
   zeropoint instead?

--The motivations for the mixing curve anchors were purely empirical.  I
  originally used SINGS objects as the anchors, but the SINGS sample
  simply doesn't fill enough parameter space to provide useful anchors.

  -Paragraph 5, Sentence 2: "Hence, strong low excitation..."  what is
   a strong low?  "Hence, strong low-excitation..."

--Done

  -Paragraph 5, Last Sentence: "Nonetheless, we present..."  This
   needs to be rewritten or chopped into two sentences, it was very
   hard to follow.  ie. if you remove the part "prominent cooling
   line..." the sentence no longer makes sence.

--Fixed

-Section 4.4.3:
  -Second to last sentence...I am not sure how obvious the trend of
  AGN -> HII nucleus -> HII region sequence is, but think it is OK for
  the paper.

--OK

-Section 4.4.4:
  -When introducing Figure 6, there is no mention of normalizing the
  lines with the 24mu data.  I was expecting a line ratio plot until I
  actually flipped to the figure.  Maybe take 1 or 2 more sentences to
  describe the plot.
  
--Fixed

-Section 5 (summare)
  - Sentence 2: "The are no SINGS sources suffciently BURIED..."
  Buried under what?  how about "..sufficiently obscurred by dust..."

--Fixed, though I may eventually remove this sentence

FIGURES:

Figure 1:  Say "BPT" in the caption as you do in the text to make it
crystal clear that this is the figure you are talking about

--This comment has made me reconsider the use of the acronym "BPT".  
  Since I don't use it anywhere else, I have removed it.

Figure 4:  Note in the caption, like you do in the text, that the low
Z (LMC and SMC points) seperate into the top right corner of the
plot.  It is hard to look at the plot quickly and just tell.

--Done.  I have improved the presentation of these plots.  It is now
  much easier to pick out the SMC/LMC data.

Figure 5: Again, mention that the SMC and LMC points seperate since
this is the most cluttered of all the plots.  Perhaps also mention
this trend of AGN-> HII(nuc)-> HII region sequence in the caption as
well.  

--I have improved the presentation of these plots.  It is now
  much easier to pick out the SMC/LMC data.