Toughest questions from children that parents struggle to answer..

A survey of 2500 parents, commissioned by the makers of 'What do kids Know?" programme on "watch" channel in UK lists the toughest questions from children that parents struggle to answer......

01. How is electricity made?
02. What are black holes?
03. What is infinity?
04. Why is the sky blue?
05. Why do we have a leap year?
06. How do birds fly?
07. Why does cutting onions make you cry?
08. Where does the wind come from?
09. Why is the sea salty?
10. How big is the world?
11. What happens to us when we die?
12. What is a prime number?
13. Is god real?
14. What makes thunder?
15. Why do you blink?