Identify the hidden meaning behind this picture?

O_er_t_o_

Complete the missing letters of the given word.

Can you solve the below tricky visual equation?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

Forwards I am heavy, backward I am not. What am I?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

What seven-letter word has hundreds of letters in it?

Name a key which is hardest to turn.

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

What can you catch but never throw?