She studied English because she wanted to become a professional writer.

VOA: special.2010.03.14

So Musorgsky knew this law of acoustics because he was a professional musician and was playing off of it to create this rather unusual and remarkable musical sound-scape here.

穆索尔斯基明白这个声学规律,因为他是位专业的音乐家,他通过制造这非凡卓越的音乐场景,表达了这个规律

耶鲁公开课 - 聆听音乐课程节选

Because in Germany everything is like, sorted out for you and very professional.

因为在德国，一切都给你整理好了，很专业。

一见钟情的学校 - SpeakingMax英语口语达人