Answer:
They are grouped on basic and shared characteristics.
The answer is gene pool, evolution, natural selection, and mutations.
C. Mammary gland. Hope this helps!
They have to do a lot of testing to see which is right and get push one aside
Fresh water is most important to our survival because we need to drink it and we use it to grow crops and produce food and trees require it to grow and we need lumber to build homes and shelters