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: What is that thing we buy for eating but cannot eat it?

Question: Leap Year is every 4 years. True or False ?

Question: What disappears as soon as you say it?

Question: I can fly in your mind. I was not made to scare anyone, but many fear me. What am I?