Answer:
I usually wear a yellow coat. I usually have a dark head. I make marks wherever I go.
Only two backbones and thousands of ribs.
What can answer in any language? What can speak without a mouth? What can sing without an ear?
Upon me you can tread, though softly under cover. And I will take you places, that you have yet to discover. I'm high, and I'm low, though flat in the middle. And though a joy to the children, adults think of me little.
What gets closer when you blink?
What covers its face with its hands, speaks no language, yet most known what it's saying?