Before revision:  We implemented a masked answer entity extraction task with an interactive learning environment , containing a question generator and a question extractor . Given a passage with a mask, a question generator asks a question about the masked entity, meanwhile the extractor is trained to extract the masked entity with the generated question and raw texts.
After revision:  REGEX is built upon a masked answer entity extraction task with an interactive learning environment , containing a question generator and a question extractor . Given a passage with a mask, a question generator asks a question about the masked entity, meanwhile the extractor is trained to extract the masked entity with the generated question and raw texts.