I make two people out of one. What am I?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

How many letters are in the alphabet?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

What part of the chicken has the most feathers?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

Jenifer and Jesica are having a conversation.

Jenifer: I am definitely not over 30.
Jesica: I am 28 and you are surely 5 years older to me at least.
Jenifer: No, you are at least 29.

You are told that both of them are lying throughout in the conversation. Can you find their respective ages?

What does a man do only once in his lifetime, but women do once a year after they are 29?

What is the Surname of Barbie Doll?