Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Give it food and it will live; give it water and it will die.

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

O_er_t_o_

Complete the missing letters of the given word.

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?