The deposition of \( X \) and \( Y \) on ground surfaces is referred as wet and dry depositions, respectively. \( X \) and \( Y \) are:
\( X = \mathrm{CO_2} \) , \( Y = \mathrm{SO_2} \)
\( X = \) Ammonium salts, \( Y = \mathrm{CO_2} \)
\( X = \mathrm{SO_2} \) , \( Y = \) Ammonium salts
\( X = \) Ammonium salts, \( Y = \mathrm{SO_2} \)