I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

Do You See It?

The day after tomorrow will be three days before Tuesday. Can you find out what is today?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

Consider this about a word: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?