foe

在比赛中，他遇到了一个强大的对手。

He faced a tough ___foe in the competition.

塑料污染是海洋生物的一大威胁。

Plastic pollution is a serious ___foe to marine life.

勇士举起盾牌，准备迎战他的敌人。

The warrior raised his shield, ready to face his ___foe.