Hard tricky riddles with simple answers

It's 7:00 am. You are asleep and there is a sudden knock on the door. Behind the door are your parents, who came to have breakfast. In your fridge: bread, pasteurised milk, juice, and a jar of jam. What will you open first?

Imagine you are in a sinking rowboat surrounded by sharks. How would you survive?

There was a plane crash every single person died. Who survived?

What am I?

While I am in air, I am not in oxygen. I am also in water, but not in hydrogen. I am necessary in all animals, but you won't find me in the zoo. Look in all brains and you'll find me there too. What am I?

Imagine you're in a room that is filling with water. There are no windows or doors. How do you get out?