holecard

例句：

1. 1. The hole card was a crucial part of the game.
   洞卡是游戏的关键部分。
2. 2. He used a hole card to win the hand.
   他使用洞卡赢得了手牌。
3. 3. The hole card was revealed during the auction.
   在拍卖中揭露了洞卡。