Answer:
Everyone has me and no one can lose me. What am I?
What comes once in a minute twice in a moment but never in a thousand years?
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?
Upon your lonely journey I accompany you, whether you travel through endless mountains or seas of blue. Wherever you go, I keep your place. Lost you're not, when I'm embraced. What am I?
I transfer oxygen from the atmosphere to your blood
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.