Reef Shorts I Need Help With Some Science Stuff That Was Suppose To Be In My Text Book But Wasn't?

I need help with some science stuff that was suppose to be in my text book but wasn't? - reef shorts

1. How natural coral reefs built?
2. Why are not too short coral reefs so important?
3. What impact have damaged or destroyed coral reefs in coastal areas?
4. Name three structures that were sunk in the sea to serve as artificial reefs.
5. What are Reef Balls?
6. Name three advantages of the Reef Balls have spread to other types of artificial reefs.
Why is it necessary for the Reef Ball with holes in the entire structure?