1.turn sth on its head 完全改变
He decided to turn this research on its head by studying young healthy men.
他决定调转研究方向,研究健康的年轻人
2.be reluctant to do 不愿做某事
But in practice, countries are reluctant to do so, fearful that an excessively strong currency will hurt their exporters.
但在实践中,各国都不愿意这样做,担心货币过度强势会影响出口