What is the structure of $L$-glyceraldehyde?

Which of the following compounds does not give a test with ninhydrin but gives a positive test with Benedict's solution?

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 $C-3$)

In $D-glucose$ $(X)$ and $D-fructose$ $(Y)$,which hydroxyl group participates in hemiacetal/hemiketal formation?

What are the two structures of $D$-glucopyranose obtained from $D$-glucose called?

Only two carbon atoms of glucose participate in the formation of osazone because they undergo .......