Why has the US had a harder time with the virus than Europe? Why does contact tracing seem to be working in some places but not others? Does it make sense to wear face coverings outside? Can COVID-19 be killed in the freezer? Can I get COVID-19 from a pool? What about in an elevator? Dr. Tom Inglesby of the Center for Health Security and Dr. Josh Sharfstein address your questions submitted to [email protected]