You have one main actor and the rest are supporting roles.

你有一个主角，其余的是配角。

youdao

Wangshijun as a main actor played a key role in the reclamation.

王士俊作为这一开垦案的主要责任人，在开垦中扮演了主要角色。

youdao

The stuntman will double for the main actor during the action scenes.

一些动作场景中，特技演员代替主演。

youdao

As NATO's main actor, America would rather work through the alliance, or through individual countries.

ECONOMIST: Charlemagne: Europe and America | The

Europe would have to be the main actor in its own backyard.

BBC: Will Sarkozy get a statue in Tripoli?

Today, Thompson knows his actor identity is the main source of the name-and-face recognition that makes him viable in national politics.

NPR: Reagan Sequel? Hard Act for Thompson to Follow