Good Riddles

Question: How many times can you subtract 10 from 100?

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

Question: People pick me, and watch me until they give me power. Then they don't stare in my eyes. What am I?

Question: Once you are in my sight, you are gone in a flash, and people tend to use me for cash. I am often used as a dire assist, and people often believe that I cause harm, when I am but its catalyst. What am I?

Question: What flag has five circles in it?