那位富商给情妇买了辆车，但从不让她出现在公众场合。

The wealthy businessman bought a car for his ___mistress but never allowed her to appear in public.

庄园的女主人严厉地管理着所有仆人。

The estate's ___mistress strictly supervised all the servants.

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.