Change to active
the baby was carried by the kangaroo in her pouch
the fire was extinguished .
the computer is being working upon by her .
The kangaroo carried the baby in her pouch.
He extinguished the fire.
She is working upon the computer. (The passive for this should be: The computer is being worked upon by her.)
He extinguished the fire.
She is working upon the computer. (The passive for this should be: The computer is being worked upon by her.)