21. How will this position injure your lungs?
22. What other bones may be injured by wrong positions?
23. Why do old people's bones break easily?
24. How should the feet be cared for?
25. How does tobacco affect the bones?
26. What do doctors say of its use?
27. What is said about cigarettes?
28. What about chewing tobacco?
29. To whom is tobacco a great enemy? Why?
30. What is always true of its use by youth?