26. (i) Write down the three letters each from the above list which are relevant to:- (Type in the selected letters separated by commas. Leave no spaces around the commas.) (1) Zinc   27. (2) Aluminium.   28. (ii) Fill in the blanks using the most appropriate words from A to F:- (l) The ore from which Aluminium is extracted must first be treated with _______ so that pure Aluminium oxide can be obtained.   29. (2) Pure Aluminium oxide is dissolved in _______ to make a conducting solution.   30. (iii) Write the formula of Cryolite.