New research indicates that many students are spending a significant amount of the school day on smartphones, but not everyone wants the devices banned. A partial government shutdown is lengthening travel delays at some U.S. airports. We're quizzing you on the signers and content of the Declaration of Independence. We're explaining how the breath and sweat of tourists has necessitated a cleaning of the Sistine Chapel. And we're exploring history related to two global pandemics. Plus: underwater martial arts in Malaysia and a unique race in the U.K.!