Answer:
I go around in circles but always straight ahead never complain no matter where I am led. What am I?
I can be sweet or sour. I do not rhyme with any other word
My snake-like body cracks and burns. I cause pain but pleasure too. What am I?
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
When you need me, you must find me. When you find me, you no longer need me. What am I?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.