1. Look a gift horse in the mouth 好心当成驴肝肺
Never look a gift horse in the mouth, ok? Take it or leave it.
别对礼物挑三拣四的好不好？要就要，不要就拉倒！
释义：别对人家送的礼物挑三拣四，吹毛求疵。源于希腊故事——特诺伊木马，伸头看马嘴里有无敌人。
2. Lose one's edge 不在状态，发挥不好
How come I missed the target all the time? I think I'm just losing my edge today.
今天我怎么老是脱靶？可能是状态不好。
释义：
edge: 刀锋，刀刃
lose one's edge: 刀刃钝了，刀锋折了，引申为状态不佳。
