Which among the following statement(s) is(are) true for the extraction of aluminium from bauxite?

$(A)$ Hydrated $Al _2 O _3$ precipitates, when $CO _2$ is bubbled through a solution of sodium aluminate.

$(B)$ Addition of $Na _3 AlF _6$ lowers the melting point of alumina.

$(C)$ $CO _2$ is evolved at the anode during electrolysis.

$(D)$ The cathode is a steel vessel with a lining of carbon.

In the reaction ${B_2}{O_3} + C + C{l_2} \to A + CO.$ The $A$ is

An element $A$ dissolves both in acid and alkali. It is an example of

In electrolysis of aluminium oxide which of the following is added to accelerate the process

$STATEMENT$-$1$: In water, orthoboric acid behaves as a weak monobasic acid. because

$STATEMENT$-$2$: In water, orthoboric acid acts as a proton donor.