Answer with Explanation:
"Moderate activity" is any activity that allows you to talk while doing it while a "vigorous activity" is any activity that doesn't allow you to talk while performing it.
An example of a moderate activity is "walking." You may have noticed that most people with friends talk while they walk. This is because their heart rate is not that fast, and it doesn't affect much of their breathing.
An example of a vigorous activity is "running." People who run don't have the energy to talk, or if they ever do, they pause for a bit. This is because their heart rate is very fast, and this affects their breathing. Thus, it is not common to see people running side-by-side while talking.
