Answer:
When it comes to me, you go on red and stops on green. What am I?
I am flora not fauna. I am foliage not trees. I am shrubbery not grass.
I'm white and used for cutting and grinding. When I'm damaged, humans usually remove or fill me. For most animals I am a useful tool. What am I?
I follow you all the time and copy your every move but you can't touch me or catch me. What am I?
A single syllable do I claim black was my most famous name; Fetal to mortals here below thousands have I slain in a single blow.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.