Logic Riddles

Question: A man builds a rectangular house. After he builds the house he wants to place a clock on a south wall. Because there are so many south walls he places the clock on a random wall. He sits in front of the sits in front of the clock for ten minutes until he hears a knock on his font door. The man opens the door to see a bear on his front porch. The bear kills him. What color was the bear and why?

Question: What is the only question you can never answer?

Question: The sky is blue, the sea is green. The answer never ends in-between.

Question: There is a wood house and a brick house that was on fire at the same time. Which house would the ambulance come to first.

Question: There are three doors: First door~ all kinds of snake will strike you once you've entered this door. Second door~ about thousands of skillful assassins are waiting in this door. Once you've entered, they will attack you to death until there are no bones left. 3rd door~ a desert, you will be die any minutes. Because there's no water (exhaustion) and from extreme the heat of the sun. Which door would you choose? Which door you think that is safe to enter???