a plan or piece of information kept secret until it becomes necessary to use it
手中握有王牌；有應急妙計
have all the advantages
占盡優(yōu)勢
use one's best resource
打出王牌；使出絕招
deciding to play her ace, Emily showed the letter to Vic.
艾米麗決定使出殺手锏，把信拿給維克看。
On the verge of; very near to
差一點，幾乎；非常接近
came within an ace of losing the election.
幾乎失去競選
A hidden advantage or resource kept in reserve until needed.
錦囊妙計：隱藏的優(yōu)勢或資源，一直保存到需要時