What describes an arrangement of repeating shapes that have no spaces or overlaps between the shapes?

Which system revise and send electrical signals throughout the body

Ausable water source is one that can be used by humans for drinking or agriculture. identify the water reservoirs as usable or unusable based on their current state. oceans rivers glaciers freshwater lakes groundwater

When listening the levels of orginization in orginisims from the smallest to most complex , which level is just below organs in complexity