挂帅的英文：
assume leadership; be in command

参考例句：

The new managing director will act as spearhead of the campaign.
新上任的常务董事将在这场运动中挂帅.

The Don must be told and he must either take command or order Hagen to surrender the Corleone power to the Five Families
必须让老子知道这个消息，他要么必须亲自挂帅应战，要么命令哈根向五大家族投降，把考利昂家族的大权拱手交给人家。

assume是什么意思：
v. 假定；臆断；采取；承担；呈现；夺取，继承；装腔作势

The responsibility for the accident was assumed by me.
事故责任由我承担。

To state or assume as a proposition in an argument.
假设，预设命题在论证中做为一命题陈述或假设。

take up (=assume) this mission
承担这使命

leadership是什么意思：
n. 领导层；领导；领导才能

They jockey for the leaderships of the party.
他们不择手段谋取党的领导权。

A change of leadership alone will not be enough.
仅仅更换领导层是不够的。

That was the first generation of collective leadership.
这就是我们党第一代的领导。

command是什么意思：
n. 命令；指挥（权）；控制，掌握；部队；指挥部；指令
v. 控制；命令；指挥；博得；俯瞰
adj. 指挥的

command sympathy
博得同情

the second in command
副司令员

commanding adj.
指挥的；威风凛凛的；居高临下的