What has many keys but can’t open a single lock?

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

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

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.

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?

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?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

I have an eye but still cannot see.

Who am I?