Which one of the following compounds contains $\beta-C_{1}-C_{4}$ glycosidic linkage?

In aqueous solution, glucose remains as:

Which of the following pairs will give the 'Tollens' test'?

Identify the number of structures from the following which can be correlated to $D$-glyceraldehyde.

Identify the product obtained when sucrose is treated with conc. $H_2 SO_4$.

Reactions with sugars are easy in acidic or neutral media,but not in alkaline media,because in alkaline media,sugars undergo.............