Good Riddles

Question: I am the beginning of the end, the end of every place. I am the beginning of eternity, the end of time and space. What am I?

Question: I'm the eyelid to your life and hide you when you're inside.
You can draw me and you can pull me, but you must leave to see my good side.

What am I?

Question: What single line can you add to the following statement to make it true?

5+5+5=550

Question: A man wants to buy a used car. He finds a beautiful Buick for $9500, but he buys it without paying a dime.

How did he manage this?

Question: Half of those who read this riddle, I am your best friend.
I depend on you, but it's you I will defend.

What am I?