Answer:
What gets closer when you blink?
Runs smoother than any rhyme, loves to fall but cannot climb!
What comes once in a minute, twice in a moment, but never in a thousand years?
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.
Salty water everywhere but not sea in sight.
They are many and one, they wave and they drum, Used to cover a state, they go with you everywhere.