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?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

I know there are two methods by using three time the same number with a plus(+) operator , you can make sum as 60.

One of them is 20+20+20.

whats the other way ?

The more of this there is, the less you see. What is it?

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.

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

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.

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

What has one letter and starts with an E?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?