Answer:
If you drop me I'm sure to crack but give me a smile and I'll always smile back. What am I?
My teeth are sharp my back is straight to cut things up it is my fate.
I am always in front of you, but you will never see me. What am I?
I can be thin but not fat; in your body but never on your placemat. I'm always better when I'm fresh but you'll never see me in the flesh.
I climb higher as I get hotter. I can never escape from my crystal cage.
If I say "everything I tell you is a lie", am I telling you the truth or a lie?