Epimers are monosaccharide diastereoisomers that have a single asymmetric carbon. Anomers are diastereoisomers in which the hemiacetal carbon of a cyclic monosaccharide is asymmetric.
Determine whether each pair of monosaccharides consists of epimers, anomers, or an aldose‑ketose pair.

1) D-glucose and D-mannose
2) D-glucose and 1 fructose
3) D-galactose and D-glucose
4) D-glyceraldehyde and dihydroxyacetone
5) D-ribose and D-ribulose