动脑

• beat one's brains
• put one one's thinking cap

例句

1. 在有些猜谜游戏中，你必须始终积极开动脑筋。
   In some of these guessing games you need to be on your toes all the time.
2. 有些学生很懒惰；另一些则勤动脑筋，因而学有所成。
   Some students are lazy, but others beat their brains and succeed.
3. 快点，你们这群笨蛋--开动脑筋嘛！
   Come on, you dozy lot use your heads!