You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

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

Explain?

I am white when I am dirty, and black when I am clean. What am I?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

Can you find the missing piece of the Porsche?

What is more useful when it is broken?

What breaks yet never falls, and what falls yet never breaks?

Lifeless eyes on my smiling face and watch your child's sleeping place. In their dreams they hold me tight. What am I?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?