Answer:
What is often returned, but never borrowed/
What goes with a car, comes with a car, is no use to a car but a car cannot move without it?
I'm light as a feather, yet the strongest man can't hold me for more than 5 minutes.
Has no feet, but travels far. Is literate, but not a scholar. Has no mouth, yet clearly speaks.
A serpent swam in a silver urn, A golden bird did in its mouth abide, The serpent drank the water, this in turn, Killed the serpent. Then the gold bird died.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.