Which of the following best explains why multiple exercises are needed to improve muscular strength and endurance throughout the body?
a. push-ups don't exercise leg muscle groups.
b. different exercises are needed to improve different muscle groups.
c. weight lifting is more important for muscle strength than endurance.
d. not all muscle groups can be exercised simultaneously.

B. Different excercises are needed to improve different muscle groups.

Explanation:

Answers A and C are too specific to their indivudal excercises and irrelevant to the question, and D disregards excercises that work out various parts of the body at once. B encompasses what you are trying to answer with the question, explains why different excercises are important, and is general enough to fully adress the broad question.

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