Answer:
Things here are usually tagged with red stickers.
I have a straight back and sharp teeth to cut objects.
I am a bow that can never be tied or broken but can disappear. What am I?
Good memory, skin like the sea. A great beast I am, yet vermin frightens me. What am I?
You can drop me from the tallest building and I’ll be fine, but if you drop me in water I die. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.