beat (或 cudgel, rack) one's brains 绞脑汁，苦苦动脑筋 Our scientists are beating their brains (out) trying to come up with a solution to the problem. 我们的科学家正绞尽脑汁，力求找到解决这个问题的办法。 The commander racked his brains over the problem of crossing the river. 指挥员苦苦思索渡河问题。