Answer:
I'm not man's best friend, I'm their enemy, I can mark your end, yet you do not see me, I am very small, but very tough, If you have me, then you have it rough.
What get wet while drying
What is that over the head and under the hat?
A great mysterious place that the bold have been known to journey into.
What two things can always see what the other sees, but can never see each other?
What did the piece of wood say when he saw the screwdriver and screws approaching?