Racial differences in health grow smaller in the oldest populations and African Americans who survive to join the oldest-old category have a slightly longer life expectancy than whites of the same age.

That is True.

Explanation:

Many studies have attributed the crossover to the “survival of the fittest,” suggesting that difficult conditions faced by African Americans during their younger ages made the weakest ones among cohort to high mortality with only the most strongest reaching old age

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

she forgets to repeat her message as often as necessary