Answer:
I'm white and I'm used for cutting and grinding. When I'm damaged people usually remove me. What am I?
When it comes to me you go on red and stop on green.
I am the noise Santa's reindeers make
The shorter I am, the bigger I am. What am I?
I've been around for millions of years, but I am no more than a month old. What am I?
The answer I give is yes, but what I mean is no. What was the question?