Good Riddles

Question: Every time a man lies his nose grows to 150 percent of its size. Every time he tells the truth it shrinks to 50 percent of its size.

What will happen if he alternates between lies and the truth?

Question: What has a neck but no head?

Question: This is a bus:

 ____________________
|       |_|    |_|    |_|    |_|       |
|                                        |
|____________________|
     O                         O

Which way is the front of the bus facing (left or right)?

Question: If a man carried my burden, he'd break his back.
I am not rich, but I always leave silver in my track.

What am I?

Question: I have roots that nobody sees,
I'm taller than any trees,
up and up I go,
but I never grow?

What am I?