Passive Voice
In passive voice, there is a greater emphasis on the action than on the subject.
Example:
Julia watered the flowers. ⇒ The flowers were watered by Julia.
Answering the Question
We're given:
I will show Mirabel Madrigal's postcard from Italy to the class tomorrow.
- Subject: I
- Action: Show Mirabel Madrigal's postcard from Italy
Let's rearrange the sentence to begin with the action/put more emphasis on the action:
Mirabel Madrigal's postcard from Italy will be shown to the class tomorrow.
Answer
Mirabel Madrigal's postcard from Italy will be shown to the class tomorrow.
