配平化学方程式
①______Al+______CuSO4═______Al2(SO4)3+______Cu
②______Zn+______HCl═______ZnCl2+______H2↑
③______C2H4+______O2═______CO2+______H2O
④______Fe2(SO4)3+______NaOH═______Na2SO4+______Fe(OH)3.