I would say A since it is closest to the mouth of the volcano and says 20 cm
Answer:
We could use up all of them right away and not have the resources for humans and animals to survive.
Explanation:
Right now, we are using our natural resources at a consistent rate. We sometimes use to many of them in one day. If we continue using up our natural resources at the rate we are right now. We may not have the necessary resources to survive in about 10-20 years.
Hope this helps!
Could be anything that can help represent the cell membrane visually
The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
