assume the office of; hold the post of
take the chair
担任会议主席
ride shotgun
担任警戒 （对运送中人、物）
take charge
担任领导
act as amiables compositeurs (of arbitrators)
担任友好调解人
be charged with the preparatory work
担任筹备工作
serve [act] as referee
担任裁判
be the chairman of a trade union
担任工会主席
conduct
担任乐队指挥
invite them to be advisers on after-school activities
请他们担任校外辅导员