What is full of holes but still holds water?

Complete the table series riddle by finding the number that can replace "??".

What jumps when it walks and sits when it stands?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Where do you go to learn how to make ice cream?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

In an office's desk, you find a unique method that shows the current day of the month. Two numbered cubes are used to depict the current date.

Can you find out the numbers on both the cubes so that each date can be mentioned using them?

Please note that you have to use both the cubes to display any date. Thus the 1st day must be represented by 01 and so on.