Before revision:  Crowdworkers created the questions and  answers based on a set of over 2,030 online Vietnamese news articles from the VnExpress news website , where the answers comprised spans extracted from the corresponding articles.
After revision:  Crowdworkers created the questions and their answers based on a set of over 2,030 online Vietnamese news articles from the VnExpress news website , where the answers comprised spans extracted from the corresponding articles.