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: "The politician who defeated Vincent C. Gray in the primary of 2014 previously served which ward?" whose answer is Ward 4.
Each document should contain about 30 words, and these documents should contain useful information.

Query: who defeated vincent c. gray in the 2014 primary and which ward did they serve
Useful Output:

Doc 1: On the ballot in D.C.: The potential political comeback of former mayor Vince Gray and an effort to make the District the 51st state.
Doc 2: In DC's Ward 7, mostly east of the Anacostia River, former mayor Vince Gray is running to take back his old seat on the DC Council from
Doc 3: Anthony Lorenzo Green, an advisory neighborhood commissioner for the Deanwood neighborhood in Northeast DC, entered the race Friday, filing
Doc 4: Muriel E. Bowser won a stunning upset on Tuesday in the Democratic primary for mayor in a race that turned on the integrity of the incumbent
Doc 5: On April 1, 2014, I will cast my ballot for Vincent C. Gray for mayor. It was an easy decision for me but may not be for many other voters.