What has one letter and starts with an E?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

What breaks yet never falls, and what falls yet never breaks?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

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

What Is It?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?