Learning and teaching virtually has been a challenge for everyone, but 91-year-old Charles Krohn is determined to keep teaching. He is a professor at the University of St. Thomas Houston and was captured in a photo taken by his daughter, Julia Krohn Mechling, sitting at a computer while teaching his students virtually. She posted the image on her Facebook page on September 1 and it has since reached thousands. Julia's caption reads: "My father has been a professor of English at The University of St. Thomas for 50+ years. Here he is, at 91 years old, embracing virtual teaching like a BOSS. Listening to and watching him teach Homer's "The Odyssey" is a true gift. He's been teaching it for decades, and yet...