Brain benders . Riddle me this

Riddle me this

Can you answer each of these riddles?

1. What did the bee say to the flower?

Hello, Honey.

2. What is that which every one can divide, but no one can see where it has been divided?

Water.

3. What is black when you buy it, red when you use it, and gray when you throw it away?

Charcoal.

4. What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Noon.

5. I'm white, and used for cutting and grinding. When I'm damaged, humans usually remove me or fill me. For most animals I am a useful tool. What am I?

Teeth.