Alex questions at night

Alex (age 6) has started asking me one question a night about something he has thought of.  Most if the time it is all him, some of the time it happens to go along with things we read about.  

Memorable questions:

How does blood get in a baby?

Why are teeth sharp?

Why is snow cold?

How do eyes work?

How can you tell money is real?

How are Legos made?

How does the color in pens get made?

Why are beaver teeth so strong?

How many balloons would it take to lift a house?