a, \(KH:K\left(I\right);H\left(I\right)\)
\(H_2S:H\left(I\right);S\left(II\right)\\ CH_4:C\left(IV\right);H\left(I\right)\)
b, \(FeO:FE\left(II\right);O\left(II\right)\)
\(Ag_2O:Ag\left(I\right);O\left(II\right)\\ SiO_2:Si\left(IV\right);O\left(II\right)\)