Silence your smartphone, but don’t put it away. Some Chinese cinemas are trying out new “bullet screens,” enabling members of the audience to project texted comments in migrating “bullets” superimposed on the big screen as the feature plays. In a nod to young moviegoers, promoters even invite snarky commentary — it’s half the fun, they say. The other half? The 10 cents the front office gets for each projected cheap shot.