duel|dueled|dueling

两位骑士将在日出时决斗。

The two knights will ___duel at sunrise.

两位骑士为争夺公主的芳心在城堡前决斗。

The two knights ___dueled in front of the castle for the princess's favor.

男孩们在后院用泡沫剑决斗。

The boys were ___dueling with foam swords in the backyard.