Good Riddles

Question: Resurrected, they descend by the millions. Sometimes, to nourish and give life. Other times, to take lives or destroy. They have been known to fill entire valleys and block roads only to disappear before executing their long journey back to the top. What are they?

Question: A smart landscaper is given the task of placing 4 trees so that they are all the same distant away from each other.

How does he do this?

Question: Flies hate us with a passion, who are we?

Question: If you're in 3rd place and you passed the person in 2nd, what place are you in?

Question: Drop me and the world will shatter,
and you can always find me where you empty your bladder.

What am I?