The authors have addressed the scientific comments by the two referees in sufficient detail. After reading the revised paper by myself, I have several (mostly technical) issues that still should be corrected before accepting this paper for publication.

First, in section 3.4 and elsewhere, the authors should not confuse between the strength (R values) and significance (p values) of the correlations when discussing the results. Now, throughout section 3.4, the authors refer to significance of the correlation even though in most cases it is actually the strength of the correlation that is meant (e.g. in figure 10 the correlation is moderate to strong for 6 cases and non-existent for the 2 other cases). Please correct.

Second, the comparison of percentages on lines 541-545 is not quite correct. E.g. if the proportion in A is 12% and in B it is 10%, then this proportion is not 2% higher in A compared with B. Please give only absolute percentages of these proportions, and when comparing different sites, simple state qualitatively to which direction they are between different sites (e.g. slightly larger than…).

Third, there are a number of sentences that are unclear and should be modified, either grammatically or otherwise. I list their locations below:

l320-323
480-481 (what is meant by fluctuating trends?)
487 (are you referring to pollutant concentrations here, please specify)
505-507
528-530 (high density of countryside?)
569-571
588-590
685-687

Finally, there are a number of minor technical and grammatical issues that should be corrected:

throughout the paper: difference in, not of

line 271: …sites were almost the same (4.8) when ….
277-278: …rural areas, whereas…transportation, were…
290-291: … matter with an aerodynamic diameter…
303: …levels can still be larger than 1000…
309: … combustion, which … region, was…
324: There are…
338-340: please delete the last 4 “the” from the list (only the first one should be there). Also delete “method” from the end.
364: delete “p.m.” 15:00 already reveals that it is in the afternoon
367: 10 mL of ultrapure
369: … before the analysis, and the …
374: … 10%, and the ….
377: in the same way
383: A chemical mass closure…
438-440: Meteorological data, including…temperature and barometric pressure, as well as air quality index (AQI) based on PM … and WD, were obtained….
450: …for each sampling day.
465: delete “obviously”. The values are, or are not, positive.
481: differences
483: especially the wind speed
488-489: …considere similar because…
508-509: …due to the lack of any control measures, as strong…
513-514: please move the citation to the end of this sentence
515-516: … process can be as high as… (is this what you mean here?)
575: should this be “relations” rather than “correlations”?
584-585: …a dominant…periods.
594: … very reactive, favoring secondary organic aerosol (SOA) formation (Zhang…)
600: …would be smaller during…
630: have been reported to be…
632: , which is at least…

This manuscript can be accepted for publication in its present form.

Editor