Suppliers(sid; integer, sname: string, address: string) Parts(pid: integer, pname: string, color: string) Catalog(sid; integer, pid: integer, cost: real) where the underlined attributes are the primary keys. The following foreign keys also exist: Catalog sid Suppliers, Catalog pid Parts Write the following queries relational algebra 1. Find the names of green parts that are supplied by HomeRepot (supplier name) with a price of $49.99 2. Find the sids of suppliers who supply some red parts; 3. Find the sids of suppliers who supply only red parts but no green parts; (hint: set difference ...) 4. Return the names of suppliers who are selling a red part and a part (of any color) with a price of \$49.99; 5. What is the most expensive item in the catalog? Return the part D; 6. Find the snames of suppliers who supply EVERY green part; 7. Are there any parts that are not being sold by any suppliers? 8. Find the names of parts that are sold by at least two suppliers