Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

The more it dries, the wetter it becomes. Can you tell what it is?

Which number should replace the question mark?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?

What is always in front of you but can’t be seen?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?