RS RS E E A A B B C C BL A STO BL A STO F F F F 2 2 R R E E AD E AD E RS RS STO STO F F F F 3 3 AD E AD E RS RS What Is the Respiratory System 4 Oxygen Goes In 6 14 Carbon Dioxide Goes Out Coughing and Sneezing 16 18 Breathing Is Automatic Glossary 22 23 To Learn More Index 24
What Is the Respiratory System 4
The Respiratory System
How do we breathe and why do we need oxygen? Your lungs work hard to keep oxygen flowing through your blood. This book explains how the respiratory system functions to take in the air we need to live.
