It involve both experimentation and repeated observations
I'm pretty sure it's Cells
Answer:
Metric system prefixes come before a basic unit of measure to indicate a multiple (or submultiple) of that unit. Basic metric units and what they measure include: meter (length) gram (mass)
I believe the answer is group 4
Excretory system removes all the wastes from the body through the creation of feces and Urine, maintains the PH level trough the regulation of H+ from the kidneys, and maintaining water balance by controlling the water concentration within the blood plasma during the excretion process of Urea.
From eating food. because without food no body's can live
