(a) At the 5th step, could you point to us the addition order of the materials?- ethanol- 4-MMA- Sodium Metabissulfite- Active carbon- Formaldehyde (b) What is the addition/holding time, if any, between each raw material/reagent in this step? (c) At which point do you increase the temperature? Is it after all the materials are mixed? (d) About the formaldehyde material, is it used in aqueous solution or paraformaldehyde (trimer) form?