?晴天霹雳

... a blessing in disguise：塞翁失马，焉知非福 a bolt from the blue：晴天霹雳 a lion in the way (or path)：拦路虎 ...

?突如其来的

... every cloud has a silver lining（每一块乌云后面都有银色的一面） 困难中必有希望 bolt from the blue 突如其来的 under the weather 身体不舒服 ...

?喜出望外

... Bob’s your uncle! 万事大吉！ bolt from the blue 喜出望外，让人意外 break one’s neck 竭尽全力做 ...