Answer:
You draw a line. Without touching it, how do you make the line longer?
What is yours but only used by others?
If a rooster lays an egg on the exact peak of a barn, which side does it fall?
If you count 20 houses on your right going to the store and 20 houses on your left coming home, how many houses did you count?
An archaeologist unearths a coin bearing the inscription "57BC". How does he instantly know that it's a forgery?
A doctor might remove one from the neck of a Dracula victim.