Waving can mean welcome and farewell, whereas scratching your head may indicate that you are at a loss.
挥手表示欢迎和告别，而挠头则表示不知所措。
I could see you scratching your head.
我能看到你摸不着头脑了。
All this might have you scratching your head.
所有这一切可能会让你百思不得其解。
If you're scratching your head right now, you're not alone.
如果你现在正在抓耳挠腮，你不是一个人。
Thus, you might be scratching your head and trying to figure out how to get the work done.
因此，您可能会刮伤你的脑袋，并试图找出如何让所做的工作。
Now you've scratching your head, puzzling over how to combine all of these aspects into one job.
你冥思苦想如何能把这些合并到一份工作中去。
So you're left scratching your head because you have a lot to say but you don't know how to say it.
所以你只有挠头了，因为你有好多话，却不知道该怎么说。
Nothing prevents you from writing some perfectly hideous code and then scratching your head over how you are going to test it.
您可以很轻松地编写一些非常恶劣的代码，然后费劲脑筋地想办法测试。
So don't ignore these details or speed through them; when your handy-dandy toolkit creates an error, you won't be stuck scratching your head and sending an email to support.
因此不要忽略这些细节或者简单地浏览一下，如果便捷华丽的工具箱出现了错误，您就不必挠头或者发送邮件请求支持了。
If you find yourself scratching your head trying to recall a name, run apropos (or the equivalent man -k). For example, if you're hunting for a calculator, simply type apropos calculator.
如果您正在努力回想一个命令名，那么试试apropos(或等效的man -k)。
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。
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。
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