What falls in the gray area between living and nonliving things? A. bacteria B. mold C. virus D. yeast

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

What best describes the dropping height of a ball that bounces back up to a height of 45 cm

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks