Comment 2: The inter-relationships among soil properties (e.g., amorphous manganese oxides and soil clay, soil total Hg and available Hg) made the stepwise regression results artificial. In other others, the authors could not assume they were independent variables by ignoring such inter-relationships, although some published papers have done this. The reviewer would recommend the authors to choose a better statistical method, which can exclude the inter-relationships among dependent variables, to reanalyze their data. These statistical methods could be found widely in the literature.