C-10-Q168mediumsingle_mcqCopper slag may contain— (i) Cu2O\mathrm{Cu_2O}Cu2O (ii) Cu2S\mathrm{Cu_2S}Cu2S (iii) CuCO3⋅Cu(OH)2\mathrm{CuCO_3 \cdot Cu(OH)_2}CuCO3⋅Cu(OH)2ai and iibi and iiicii and iiidi, ii and iii