Answer:
''When will the date of their wedding announced by them .''
hope it helps you it will be more helpful if you give me brainlist.
Explanation:
passive form is changed by the form
[tex]WH -word + auxiliary + subject + verb + object? (active )[/tex]
will be changed to
[tex]WH-word + Auxiliary + Object + V-3 + by + Agent .(passive)[/tex]
so in the sentence
so the will be changed by the 2nd of general form .
which uou will answer by
''When will the date of their wedding announced by them . ''
we use them b/c the subjective pronoun is in the object place they change their form to objective pronoun.