How many words can a pen with half refill write?

Decode this picture on T-Shirt and tell what it says ?

Its something that each of us devours,
Not just us but birds, beats, trees, and flowers,
Frets iron and nibbles steel,
Toil hard stones to meal,
Exterminates king, collapse town,
And blows the mountains down.

Why do we preferably have round manhole covers and not square ones?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

What does below chemistry rebus means?

How is a fly different from a mosquito?

Where do you go to learn how to make ice cream?

What has no start, end, or centre?

I am not a bull but I have horns.
I am not an ass but I have a pack saddle.
Wherever I go, I leave silver behind me.

Who am I?