Answer:
What can be heard and caught but never seen?
In marble halls as white as milk, lined with a skin as soft as silk. Within a fountain crystal-clear. A golden apple doth appear. No doors there are to this stronghold, yet thieves break in and steal the gold.
They're up near the sky, on something very tall. Sometimes they die, only then do they fall.
What has a bottom right at the top?
What do you use to hoe a row, slay a foe, and wring with woe?
People take me on walks and I run and have fun. What am I?