Question

Letters are delivered by the postman. change voice
​

Answer 1

${\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{\fbox{AnSwEr}}}}}}}}}}}}}}}}}}}}}}}}}}$

When this is changed to passive voice, the action is expressed by the predicate (position interchanged with the subject). The sentence is in a past continuous so we have to add was being and past participle of the verb.