146 GOOD HEALTH 



5. What do they try to do? 



6. What happens when the cilia have too much to do? 



7. What is worse for the lungs than mere dust? 



8. How shall we protect our lungs in dusty places? 



9. Why should we keep from talking on a dusty street? 



10. What harm does tobacco smoke do to cilia? 



11. Mention three ways in which warm, dry tobacco smoke may 

 injure a man's lungs. 



