🔍 Key Concepts

• Normal breathing air composition in basic first aid/CPR or firefighting training • Difference between oxygen needed to stay alive vs. typical room air • Approximate percentages of nitrogen vs. oxygen in the atmosphere

💭 Think About

• Think about what you learned in basic first aid or CPR: at what oxygen percentage does air become dangerously low for human life? • Which of these answer choices sounds closest to the commonly taught value for oxygen in the atmosphere at sea level? • Compare the options: which ones are clearly too low to safely support normal consciousness and physical activity?

✅ Before You Answer

• Remember that nitrogen is the largest component of air, not oxygen • Verify that the correct oxygen percentage is a value commonly taught in basic safety, firefighting, and medical training • Eliminate choices that would represent dangerously low oxygen levels where people would quickly pass out or die