Free help with homework

Why join Brainly?

  • ask questions about your assignment
  • get answers with explanations
  • find similar questions


When the air enters through our nose, it passes through the wind-pipe (tracheae) and enters the lungs. Inside the lungs, gaseous exchange takes place in structures called alveoli. Only Oxygen gas is taken in, the rest all gases are released back into the atmosphere during exhalation.
2 5 2
The Brain
  • The Brain
  • Helper
Not sure about the answer?
Learn more with Brainly!
Having trouble with your homework?
Get free help!
  • 80% of questions are answered in under 10 minutes
  • Answers come with explanations, so that you can learn
  • Answer quality is ensured by our experts