And he was very proficient at measuring atomic mass.

他对测量原子质量很精通。

麻省理工公开课 - 固态化学导论课程节选

Until you're a proficient reader of a language, writing in our language is a fool's errand.

你只有成为一个熟练的读者，才有可能成为一个好的作者。

英语阅读：技巧 - SpeakingMax英语口语达人

It turns out in the world of classical music there's a stereotype of women being simply less proficient than men: they play smaller than men, they don't have the same force and they have smaller techniques, they're more temperamental and so on.

在古典音乐界,有一个刻板印象,女人的造诣就是不如男人：,她们演奏得不如男人宏大，她们力量不如男人，她们技巧不如男人，她们喜怒无常等等。

耶鲁公开课 - 心理学导论课程节选