Answer:
<h2>Option-3</h2>
<h3>Hope it helps you </h3>
The air in alveoli has high pressure of oxygen and low pressure of carbon-dioxide.
The air in blood vessels has high pressure of carbon-dioxide and low pressure of oxygen.
What viral disease now thought to only exist inside a laboratory caused the death of many American Indians after europeans arrived in north American?
smallpox
Chloroplast makes Photosynthesis