(a.) 伪造的;假冒的
Counterfeit bills are really hard to catch.
伪钞真的很难抓。
currency 
(n.) 通货,货币
She exchanged her currency at the airport.
她在机场换钱。
have one's head in the sand
不顾事实真相；逃避现实；拒绝承认问题但又妄想情况好转；采取鸵鸟政策
It's no use having your head in the sand .You should try to solve the problem.
逃避现实是没有用的。你应该尝试解决问题。
