博物馆里展出了一个古代士兵的金属头盔。

An ancient soldier's metal ___casque is displayed in the museum.

骑手戴上防护头盔准备参加摩托车比赛。

The rider put on his ___helmet before the motorcycle race.

这种鸟的头冠在穿越森林时保护它的头部。

The bird's ___casque protects its head while moving through the forest.