I'm not 100% sure, but I'd say the availability of vaccines and medicine.
Answer:
<em>The correct option is d) an ecotone</em>
Explanation:
An ecotone can be described as an area of transition between two different biomes. An estuary can be described as an ecotone where the river water meets the seawater. The freshwater biome mixes with the seawater biome in an estuary. Unique plants and animals are grown in an estuary which are adapted to live in such an environment. The water present in an estuary is termed as brackish water. Hence, the correct option is d.
The pulmonary circulation conveys blood that is low in oxygen to the lungs before returning back to the left side of the heart.
<h3>The pulmonary circulation</h3>
The circulatory system is divided into two main parts namely:
- pulmonary circulation and
The pulmonary circulation involves the movement of blood between the lungs and the heart.
Blood from the systemic circulation returns to the right side of the heart where it is pumped through the pulmonary artery into the lungs to be oxygenated.
After oxygenation has taken place in the lungs, the blood returns to the left side of the heart through the pulmonary veins.
Learn more about systemic circulation here:
brainly.com/question/811428
I think it might be Rainfalls? That’s just what I think might be the answer
