<h3><u>Answer;</u></h3>
A. Gas exchanges takes place by diffusion.
B. It is an open system.
<h3><u>Explanation</u>;</h3>
- Most molluscs and arthropods have an open type of circulatory system.
- Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.
- Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
Answer is D.
you can learn A,B, and C from examining fossils
Answer:
The correct answer is: <em>C. Increased average lifespan to 78 in the US.</em>
Explanation:
Science has impacted human health by increasing the average lifespan to 78 in the US. Over the last couple of decades, the life expectancy of Americans has increased significantly than what it was 200 years ago. This can be attributed to:
1. Vaccinations- Since the invention of vaccinations, diseases such as tuberculosis, cholera and polio which were major causes of death 200 years ago have virtually been eradicated in the US.
2. Abundant and safer foods available- Commercial and large scale farming has made a wide variety of nutritious foods easier to obtain.
3. Improved sanitation- Safer drinking water, sewage treatment and stricter food inspection has significantly reduced the rate of illnesses due to poor hygiene and sanitation.
In these ways, science has impacted human health by increasing the average lifespan to 78 in the US.
Answer: Dolphins
Explanation:
Dolphins are well-documented as intelligent animals. They can recognize themselves in a mirror and communicate with each other. Their large brain is structured for awareness and emotion, and dolphin brains are even more structurally complex than those of humans.
