The alveoli are surrounded<span> by tiny blood vessels, called capillaries. The </span>alveoli<span> and capillaries both have very thin walls, which allow the oxygen to pass from the </span>alveoli<span>to the blood. The capillaries then connect to larger blood vessels, called veins, which bring the oxygenated blood from the lungs to the heart.</span>
Answer:
A.Because Earth's atmosphere causes most objects to burn up before they reach the surface.
Explanation:
The Earth's surface is rarely impacted by large objects that enters because the atmosphere causes most of the objects to burn up before they reach the surface.
There are different layers of the earth atmosphere which carries various amount of energy and energetic particles.
- When a massive and a high solar object or dust or rocks are directed towards the earth, they are either deflected or burnt upon their passage through the atmosphere.
- These energetic particles have ionizing properties and causes the solar particles to burn up.
- This way the earth's surface is shielded from any impact of any sort.
A temperature change in a reaction indicates a chemical change
