Answer:
Internal can be you don't want bad things happening to your body, you don't want drugs affecting your health,etc.External could be you don't want it to affect your family or people around you.For example, like a cigarette if you are smoking in public you can be affecting others passing by or hanging out with you(external)but if it's just you by yourself smoking it is damaging your lungs(internal)
The mass of one human is 62kg. Hope this helps!
The glands of the endocrine system secrete hormones into the bloodstream to maintain homeostasis and regulate metabolism.
Id say it would be all of the above. if you think about it our bodies mentally and physically need to rest so they can be "charged" and ready for theday. if you dont sleep you will be drowsy and not to be able to focus on any of the options
White blood cell, red blood cell, and plasma
