表示“……的角色”可用“the role of ...”，一般不在其后面所接的名詞前加冠詞a/an。He will appear in the role of mediator.他會(huì)出庭，充當(dāng)調(diào)停者的角色。

　　role用作名詞的用法例句

　　The Panama Canal has played a very important role in transportation.巴拿馬運(yùn)河在運(yùn)輸上起到了非常重要的作用。

　　The key role of the teacher in the learning process should not be neglected.教師在學(xué)習(xí)中的關(guān)鍵作用是不該忽視的。

　　The role of the railway declines in the transport system.在運(yùn)輸系統(tǒng)中,鐵路的重要性逐漸下降。