Question

Change the voice of :A dark haired person must play Mary Stuart.

Answer 1

Answer: Mary Stuart must be played by a dark haired person.

              Hopefully thinking that my answer will be helpful for you.

Answer 2

$\huge\underline\mathtt\orange{Answer}$

Active voice :

A dark haired person must play Mary Stuart.

Passive voice :

Mary Stuart must be played by a dark haired person.

$\huge\underline\mathtt\orange{Additional-Information}$

If you want to change an active-voice sentence to passive voice, consider carefully who or what is performing the action expressed in the verb, and then make that agent the object of a by the... phrase. Make what is acted upon the subject of the sentence, and change the verb to a form of be + past participle.