You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "what age horse runs in the kentucky derby?" whose answer is three-year-old.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Kentucky Derby age requirement
Useful Output:

Doc 1: Similarly, you may place wagers at our racetracks if you are at least eighteen (18) years old, or older in some jurisdictions, and you may
Doc 2: Only 3-year-old Thoroughbreds are eligible to run in the big race, so the competition is fierce and a second chance at glory isn't coming next
Doc 3: In order to simplify the age requirements, the Jockey Club rules state that every horse's official birthday is listed as January 1 of the year
Doc 4: Age Requirement: 18+ in most states; 21+ in AL, AZ, IA, KS, NH, ND, and WA. DRF Bets is a highly regarded betting platform for horse racing. If
Doc 5: The race is run by three-year-old Thoroughbreds at a distance of 1+1⁄4 miles (10 furlongs; 2,012 metres). Colts and geldings carry 126 pounds (57 kilograms) and