X. Find the logical continuation of the sentences

The respiratory system is Air enters the respiratory system Air breathed in is filtered Coarse hairs line the nostrils and Small particles are trapped This mucus is moved away by Air travels from the mouth through At the entry to the windpipe It closes to prevent The windpipe divides into The windpipe and bronchi are stiffened The bronchi split into The bronchioles branch through the lungs and Gases are exchanged Each airsac is meshed with Oxygen breathed in passes Carbon dioxide and water vapor are released The blood in the capillaries flows into

the throat, voicebox and windpipe. by rings of cartilage. lead into millions of airsacs of the lung tissue. the pulmonary vein and back to the heart for redistribution. through the mouth and nose where it is warmed and moistened. in the airsacs. trap large dust particles. small blood vessels (capillaries). in a sticky fluid. the network of organs and passages by which air travels into the lungs and gases are exchanged. by coarse hairs. is the flap, the epiglottis. into the blood. smaller bronchi and then into bronchioles. the beating of minute hair-like projections. choking when the food is swallowed. into the airsacs to be breathed out. two tubes or bronchi.

XI. Answer the questions to the text

1. What is the respiratory system?

2. How does air enter the respiratory system?

3. What happens with the air in the mouth and nose?

4. What is the air breathed in filtered by?

5. What particles do the coarse hairs trap?

6. What are small particles trapped in?

7. What is the mucus produced by?

8. How is the mucus moved away?

9. Where does the air travel from the mouth?

10. What is at the entry to the windpipe?

11. What is the function of the epiglottis?

12. What does the windpipe divide into?

13. What are the windpipe and the bronchi stiffened by?

14. How many bronchi enter each lung?

15. What do the bronchi split into?

16. Where do the bronchioles lead?

17. Where are the gases exchanged?

18. What is each airsac meshed with?

19. Where does the oxygen breathed in pass?

20. What is released into the airsacs to be breathed out?

21. Where does the blood rich in oxygen flow?

XII. Speak on the topics using the suggested words

1. The respiratory system: the network; passages; are exchanged.

2. Breathing in the air: through the mouth and nose; to warm; to moisten; is filtered by coarse hairs; large dust particles; small particles; sticky fluid (mucus); is moved away; the beating of the minute projections (cilia).

3. The windpipe: the throat; the voicebox; the windpipe; a flap (the epiglottis); to prevent choking; to divide into; bronchi; rings of cartilage; bronchioles; airsacs of the lung tissue.

4. Exchange of gases: is meshed with; oxygen breathed in; carbon dioxide and water vapor; to be breathed out; the blood in the capillaries; the pulmonary vein; for redistribution.