Overall, how has science impacted human health?
a. more types of surgery, so more unsafe procedures.
b. increase in pollution has lead to a decrease in average lifespan.
c. increased average lifespan to 78 in the us.
d. it has had no effect.

The correct answer is: C. Increased average lifespan to 78 in the US.

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.

the answer is "a.) well–developed vascular system."

explanation:

feral cats are estimated to eat tens of millions of native animals each night in australia