mistress

庄园里所有的仆人都很畏惧他们的女主人。

All the servants in the manor feared their ___mistress.

她是一位语言大师，能流利地说七种语言。

She is a ___mistress of languages, speaking seven fluently.

我们的法语女教师非常严格，但她教得很好。

Our French ___mistress is very strict, but she teaches well.