6. Which of the following is an L-aldotetrose? 7. Which of the following is a D-aldotetrose? 9. Which structure is D-galactose? 10. Which of these could be non-reducing monosaccharide(s)? 11. Which of these is(are) glycoside(s)? 12. Which of these are anomers? 15. Which of the following is D-galacturonic acid? 16, Which, if any, of these is a non-reducing disaccharide? 17. Which compound reacts with 3 mols of HIO4 to yield 2 mols of HCO2H and 2 mols of HCHO? 20. Which of the following would yield D-glucose and D-mannose when subjected to a Kiliani-Fischer synthesis?