晴天霹雳地,突然,出乎意料地
out of the blue adj : not anticipated; "unanticipated and disconcerting lines of development"- H.W.Glidden; "unforeseen circumstances"; "a virtue unlooked-for in people so full of energy"; "like a bolt out of the blue" [syn: {unanticipated}, {unforeseen}, {unlooked-for}, {out of the blue(p)}] adv : in a way that was not expected; "her brother showed up at the wedding out of the blue" [syn: {unexpectedly}]