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.

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

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?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

What have one eye but still cannot see?

I know a nine-letter word having only one vowel.
Do you ?

If six children and two dogs were under an umbrella, how come none of them got wet?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?