An April 16, 2019, file photo, shows a Juul vape pen in Vancouver, Wash. New research released on Tuesday, Nov. 5, 2019, shows U.S. teens who use electronic cigarettes prefer those made by Juul Labs, and mint is the favorite flavor for many of them, suggesting a shift after the company stopped selling fruit and dessert flavors in stores. (AP Photo/Craig Mitchelldyer, File)