Write half-reactions for the oxidation and reduction processes for the following:
Sn2+ + IO3- -> Sn4+ + I- (acidic solution)
MN2+ + H2O2 -> MnO2 + H2O (basic solution)
Sn2+ + IO3- -> Sn4+ + I- (acidic solution)
MN2+ + H2O2 -> MnO2 + H2O (basic solution)