fling down the gauntlet

例句：

1. 1. The CEO challenged the new manager to a friendly game of basketball.
   首席执行官向新任经理发起了一场友好的篮球比赛。
2. 2.He flung down the gauntlet to his rivals by announcing his retirement plans.
   他向竞争对手宣战，宣布了自己的退休计划。
3. 3. After winning the championship, the team flung down the gauntlet to their opponents in a friendly match.
   在赢得冠军后，球队在一场友好比赛中向对手发出挑战。