Respuesta :

Answer:

The trees were being planted by them.

Explanation:

You have to first find the subject then start you sentence with it

Answer:

Trees were planted by them.

Explanation:

Passive voice tells us what is done to someone or something.

                           {Object + verb + subject}

Trees (object) + planted (verb) + them (subject) = Trees were planted by them.

Hope this helps :)