chief

警察局长

the head of a police department

消防队长

the head of a fire department

消防部门的负责人

部落首领

the leader of a tribe

一个部落社区的领袖

村长

the leader of a village

部门主管

the head of a division of an organization

组织部门的负责人

the head of a branch of an organization

警察局长

a fixed title for the head of the police

警察负责人的固定头衔

参谋长

the most senior officer in an army, navy, or air force

陆军、海军或空军中最高级别的军官

成为首领

to start being the chief

开始担任首领

任命（某人）为首领

to officially choose someone to be the chief

正式选择某人担任首领

提名某人为首领

to name someone as the new chief

提名某人为新首领

首席执行官

the person with the most important position in a company or organization

公司中职位最高的人。

主要理由

the most important reason

最重要的理由

the main reason for something happening

主要对手

the main competitor or opponent

主要敌人

the main person or group one is fighting against

主要的或首要的敌人。