Rack one's brain 这个片语的意思就是“绞尽脑汁,苦苦思索”,例如:I've been racking my brain trying to recall where we put the key.
这个片语还可以写成是cudgel one's brains,cudgel是那种短粗的棍棒,想想看,绞尽脑汁的想一个问题还真是好比有人用棍棒敲打你的头哦。我们来看个例子:He's been cudgeling his brains all day over this problem. 他整天都在为这个问题费脑筋。
2. She beat her brains out during the examination. 在考试中她绞尽脑汁。
既然是绞尽“脑”汁,那这个表达肯定和brain 扯不开关系了。比如这个片语beat one's brains out,也是“绞尽脑汁,大费脑筋”的意思,不过这个片语通常只用在口语中,比如:Joe's beating his brains out to finish this puzzle. 乔正在绞尽脑汁解决这个难题。