在龙舟比赛中，他担任龙头，引领整个队伍前进。

In the dragon boat race, he acted as the ___dragon-head, guiding the entire team forward.

传说中这艘船的龙首雕刻能保佑水手平安归来。

Legend says the ___dragon-head on this ship protects sailors during their voyage.

在这个项目中，王教授是龙头，负责协调所有团队的工作。

In this project, Professor Wang is the ___leader, coordinating all the teams' work.