What has to be broken before you can use it?

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

What has many keys but can’t open a single lock?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

What have one eye but still cannot see?

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?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.