I stretch for miles, a ribbon unbound, Where adventures bloom and memories are found. What am I?

I have many ribs but no lungs, and I stand tall to keep you safe. I am a wall made of many parts, yet you can see the sky through my gaps if you stand close. I am often made of wood, sharpened at the top like a row of pencils, meant to discourage a climb. I am not a building, but I define where the building begins. What am I?

Silent guardian of words, resting on a shelf, unlocking a world of meanings, from A to Z it dwells. Need a spelling then come. And read thee

I carry papers on my face, And keep them steady in one place. I have a clip that holds them tight, So you can write both day and night. I’m not a desk, I’m small and light; What am I?

What is black when it’s clean and white when it’s dirty?