Which one of the following choices best represents an advantage of cardiorespiratory fi
tness

While you didn't provide any choices, we can surely say that one of the most obvious would be that you need longer and more intense physical stimulation (running a lot or performing a certain physical activity very intensely) to become fatigued compared to somebody who doesn't have any cardiorespiratory fitness. They would tire out much easily and would develop a higher heart rate much faster. 

Depression is lifelong, though you can get medication to with it. the difference between sadness and depression is that sadness lasts a little bit, depression last a long time and it goes on and off. people usually get depression through experiences they have been through, or genetics.

It would be 23 beats per second