8.	For 2,000 years on the far away island of Yap in Micronesia, located  in the Pacific Ocean, the inhabitants have been using giant stones as  money (Note: this is a true story)
 a)	What are the functions of money?  Can these stones fulfill all or partially the functions of money?
 b)	Because the stones are worthless when broken, the islanders leave the  larger ones where they are and simply take note of the fact that  ownership has changed.  How is this similar to paying by checks?