1. Even the smoking-lung cancer connection took decades of epidemiological head-scratching to figure out. 尽管吸烟能导致肺癌这个令人挠头的难题也是经历了数十年的探索才最终得出了结论。
2. We've all had a few head-scratching moments with generics, but far and away the trickiest part of generics is wildcards. 对于泛型我们都经历过一些痛苦的回忆，但毫无疑问通配符是最棘手的部分。
3. In a world besotted with gadgetry, few consumer products have generated as much excitement - and head-scratching - as high-definition television. 在这个到处都被小玩意冲昏头脑的世界里，很少有消费品像高清晰电视一样让人激动人心同时又令人哭笑不得。
4. But the result is bound to bring more chin-stroking and head-scratching: Why does Messi's Barcelona steamroll the opposition while Messi's Argentina underachieves? 但是结果必然更加令人抓耳挠腮：为什么梅西的巴萨神挡杀神而阿根廷却是潜能发挥不良呢？
5. It wasn't so long ago that trying to get Linux onto your system hard disk often comprised hours of head-scratching, system resets, and searching the Internet for the right drivers. 不久之前，在您的系统硬盘上安装Linux往往会花上您数小时去苦思冥想、进行系统重启、在因特网上搜索适当的驱动程序。
