DEAR MISS MANNERS: For the past two years, we have been living behind masks as we strive to keep from spreading, and contracting, COVID-19. Although they help reduce contagion, masks also eliminate handy facial characteristics that help us identify people. Given this constraint, I’m wondering if there might be some polite way to say, “Who are you?” when people greet me. With nothing to go on besides eye color and voice, I often have no way of knowing who they are. I don’t want to be blunt, but I don’t want to be clueless, either. GENTLE READER: A quizzical look — from a respectful distance –…