On hydrolysis,sucrose gives:

Two statements are given below.
Statement $I$: Milk sugar is a disaccharide of $\alpha-D$-galactose and $\beta-D$-glucose.
Statement $II$: Sucrose is a disaccharide of $\alpha-D$-glucose and $\beta-D$-fructose.
Correct answer is

$Glucose$ and $fructose$ are ......................... of each other.

The correct corresponding order of names of four aldoses with configurations given below,respectively,is:
$(1)$ $CHO-CH(OH)-CH(OH)-CH_2OH$ (both $-OH$ on right)
$(2)$ $CHO-CH(OH)-CH(OH)-CH_2OH$ ($-OH$ on left at $C-2$,right at $C-3$)
$(3)$ $CHO-CH(OH)-CH(OH)-CH_2OH$ (both $-OH$ on left)
$(4)$ $CHO-CH(OH)-CH(OH)-CH_2OH$ ($-OH$ on right at $C-2$,left at $C-3$)

Which reagent among the following is used to confirm the presence of an aldehydic carbonyl group in glucose?

An organic compound gives a positive result for Molisch's test as well as Benedict's test,but it does not give a positive result for Seliwanoff's test. Most probably,it is: