No question seems more relevant right now. In Europe, a number of countries are taking tentative steps to reopen. On Monday, parks and forests in Poland went back to normal. In the Czech Republic, people could go to open-air markets. In Norway, pre-schoolers went back to class with some restrictions. And Germany is taking things one step further: smaller retail stores are now allowed to reopen. And there’s the key issue: relapse. No one at this point can be sure what will happen next.