traduza para o português: "The Big Data Question Answering system employs Question Answering (QA) algorithms to query documents. These algorithms are composed of two steps: Document Retriever and Document Reader. The first step takes questions in natural language from the users as input and then queries related documents, searching for documents that may have the answer to the questions. The second step produces summarized answers from the retrieved documents." Make sure your entire response is wrapped in JSON format.
user