语法分析题: 请参考译文,提炼出该句的主句,并选择出正确的选项: Visualization-based data discovery tools allow business users to mash up disparate data sources to create custom analytical views with flexibility and ease of use that simply didn't exist before.
【单选题】听力原文:W: How is your job at the supermarket? M: Well, it's rather hard work. The hours are pretty long. I already feel difficult to keep up with my classmates. What is the man worried about? (16)