Which reagent oxidizes glucose to saccharic acid?

Which one of the following is the structure of lactose?

Which set of terms correctly identifies the carbohydrate shown?
$1$. Pentose $2$. Pentulose $3$. Hexulose $4$. Hexose
$5$. Aldose $6$. Ketose $7$. Pyranose $8$. Furanose

Anomers of glucose are defined as:

Consider the following reactions:
$(i)$ $\text{Glucose} + ROH$ $\xrightarrow{\text{dry } HCl} \text{Acetal}$ $\xrightarrow{x \text{ eq. of } (CH_3CO)_2O} \text{acetyl derivative}$
$(ii)$ $\text{Glucose}$ $\xrightarrow{Ni/H_2} A$ $\xrightarrow{y \text{ eq. of } (CH_3CO)_2O} \text{acetyl derivative}$
$(iii)$ $\text{Glucose} \xrightarrow{z \text{ eq. of } (CH_3CO)_2O} \text{acetyl derivative}$
$x, y$ and $z$ in these reactions are respectively:

What are glycosidic linkages? In which type of biomolecules are they present?