In high-school exam terms, a 62% Rotten Tomatoes rating for Man of Steel is a fail — an F. Which doesn’t mean squat, of course, in box-office terms. My 9:30 am Prague screening (Vinohradská 151, 13000 Prague) starts in 55 minutes. I’m told that last week’s early-bird digital screening for critics on the Warner Bros. lot suffered a technical breakdown, causing a full hour’s delay.