Galactose is converted into glucose in

How many products are produced respectively when optically pure glucose and fructose are reduced one by one by $NaBH_4$?

The correct observation in the following reactions is:
$\text{Sucrose}$ $\xrightarrow[\text{Cleavage (Hydrolysis)}]{\text{Glycosidic bond}} A + B$ $\xrightarrow[\text{reagent}]{\text{Seliwanoff's}} ?$

$A$ molecule of glucose reacts with $x$ molecules of phenylhydrazine to form osazone. The value of $x$ is.........

Given below are two statements.
Statement $I$: Maltose has two $\alpha$-$D$-glucose units linked at $C_1$ and $C_4$ and is a reducing sugar.
Statement $II$: Maltose has two monosaccharides: $\alpha$-$D$-glucose and $\beta$-$D$-glucose linked at $C_1$ and $C_6$ and it is a non-reducing sugar.
In the light of the above statements,choose the correct answer from the options given below.

The general formula for a disaccharide is ...... .