Answer:
They're all living things.
Step-by-step explanation:
Bacteria - This is the controversial one. Because they do not use their own energy, some scientists do not consider them alive. This is a bit of an odd distinction though, because some bacteria rely on energy from their host, and yet they are considered alive. These types of bacteria are called obligate intracellular parasites. Living things respond to their environment. However, bacteria need food, they reproduce, and some need oxygen.