Fun Riddles

Question: I can be used to build castles,
but I crumble in your hands.
I can help a man see,
and am found all around the lands.

What am I?

Question: What do you have that I use more than you do?

Question: A man is at work when he turns off the light and falls asleep. When he wakes up he discovers that lots of people have died.

What is his profession?

Question: There was a man who was born before his father, killed his mother, and married his sister. Yet there was nothing wrong with what he had done.

Why?

Question: There is a boat crash in the middle of a lake between Canada and the United States. Where do they bury the survivors?