Salt bridge

Salt Bridge is the path for the migration of ions.
Thus salt bridge's material must be relatively unreactive than electrolyte in cathode and anode.
Also, it should be soluble in water.

KSO4<=should be K2SO4.
NaSO3<=Na2SO3 or Na2SO4?
Potassium chloride(KCl)Sodium chloride(NaCl)are best salt can be used.They both have a high solubility in water.

Potassium sulphate(K2SO4),potassium nitrate(KNO3)and sodium sulphate(Na2SO4) or sodium sulphite(Na2SO3)can also be used but they have a low solubility in water.

Copper sulphate(CuSO4)has a high water solubility in water,but it easily react with others.
It is the only one cannot be used.

All soluble salts can be used except those which can react with the electrolyte in the half cells.