Answer:
Six letters it contains. Take away the last and only twelve remains. What is the word?
I have no voice but I can teach you all there is to know. I have spines and hinges but I am not a door. Once I've told you all, I cannot tell you more. What am I?
A large oasis in the desert. Come with cash and leave with none. What am I?
I sleep when you are awake, I am awake when you fall asleep. I can fly but no feathers to aid my flight. What am I?
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?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.