professional

adj.职业的;专业的;有职业的;娴熟的;训练有素的;精通业务的

n.专门人员;专业人士;专家;职业运动员;(从事某活动的)专业人员;内行;专门人才;技术精湛者;老练的人

复数： professionals

Do you belong to any professional or trade associations?

你参加了专业学会或行业协会没有？

These garments are intended for professional sports people.

这些服装是为专业运动员制作的。

The contributors are, for the most part, professional scientists.

投稿者大多是专业科学家。

He won't cut it as a professional singer.

他的歌艺未达到专业歌手水平。