Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

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

O_er_t_o_

Complete the missing letters of the given word.

If an electric train is travelling south, then which way is the smoke going?

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

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

I am the fastest animal but cannot climb the tree. What am I?

If eleven plus two equals one, what does nine plus five equal?

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

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?