Sometimes you'll start a quiz but won't get a chance to finish it in one sitting! To find articles you need to complete the quiz on, click on the Articles tab at the top. It will land you on a page to Browse Articles, but simply click on the Articles in Progress tab to find your uncompleted assignments.
Ever curious why Zinc has you make a prediction before answering a multiple choice questions? Here's a video explaining why: https://zinclearninglabs.wistia.com/medias/sk99bay7tl