Good Riddles

Question: can you make an equation by using only the no.-4,4,4,4 whose answer will be 20.

Question: What wears a black suit and watches while stalking?

Question: I'm just a lot of nothing but I'm every were... what am I?

Question: Some friends (5 friends) are climbing an oak tree to get a leaf so who got the pine leaf?

Question: A man wants to start a forest fire.There are 80 trees and you have a lighter. How many trees should he burn?