12. How does regular exercise improve cardiovascular function during
times of stress?
A. It reduces carbon dioxide supplies and raises
triglyceride levels.
B. It increases oxygen supplies and lowers
triglyceride levels.
C. It reduces the amount of endorphins released
in the body
D. It increases the level of hormones circulating
in the body.

B

Explanation:

Regular exercise improves cardiovascular function during times of stress in that: It increases oxygen supplies and lowers triglyceride levels.

to prevent people from getting the ebola virus, countries around the world paid to doctors develop a new vaccine. now that the vaccine has been made, doctors will need to experiment on a large number of people to find out if it works safely.

what is the greatest limitation that scientists are dealing with as they try to figure out how to experiment with the ebola vaccine?

meditation is a practice of sitting still and quiet for minutes or even hours. it has been practiced for thousands of years and is even a part of religious practices for some people. carefully controlled, repeated measurements of brain activity have shown that meditation does increase certain chemicals in the brain and even grows the part of the brain that people connect with their current surroundings and activities.

are claims about the effects of meditation most likely scientific or pseudoscientific?

not pseudoscientific, because people have made claims about it but scientific observations have not been made