Topic: Food Energy and Respiration Subtopic: Introduction
How does air enter our lungs?
Answer: When we exhale, there is a pressure difference inside and outside of the lungs. To maintain that pressure air enters the lungs.
Learn also:
- Why is reproduction important?
- What happens if excess lactic acid is produced?
- Why are plant roots important?
- Where are pulses felt?
- From where does roots take up oxygen?
- How long is digestive tract?


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