17=3
18=4
I'm not that sure about 17, but I think it's right
Answer:
Carbon dioxide
Explanation:
The alveoli picks up the oxygen you breathe in and releases the outgoing waste product carbon dioxide
The correct answer is D. Bird flu.
Polio and smallpox are very rare today as they were eradicated hundreds of years ago and TB has been around for maybe thousands of years. Bird f!u was discovered in 1957.