Good Riddles

Question: A hill full a hole full you cannot catch a bowl full.

Question: There are 30 cows in a field and 28 chickens....how many didn't?

Question: You wait for it. It cracks, stays for a moment, and then vanishes before your eyes. What is it?

Question: Filled with garb,
the price is free.
Just return what you don't need.

What am I?

Question: Hold me by the neck and I won't mind,
if I get wrong I just need a good wind.
If you want me you better pick wisely,
just use your ears and I'll follow you blindly.

What am I?