挑战者

例句：

1. 1. He is a challenger in the upcoming marathon race.
   他在即将到来的马拉松比赛中是挑战者。
2. 2. The company is always looking for new challengers to expand its team.
   该公司总是在寻找新的挑战者来扩大其团队。
3. 3. The young athlete is a natural challenger to his older competitors.
   这位年轻的运动员是他的老对手们的自然挑战者。