I stand where boundaries rise and fall, I keep things in and out for all, I’m silent, still, yet strong and tall.

Their tops aren't made out of rubber, Their bottoms aren't made out of springs. Not bouncy, trouncy, flouncy, though pouncy at any rate. If I could say one last thing of these beasts: 'They're grrreat!'

It's where your heart is and where your hearth is.

A thin highway that keeps no guest, Where wandering streams briefly flow. Though empty, I disturb their rest And guide them upward as they go. What am I?

Gee, it’s a type of butter. Could you clarify that for me?