Make it passive
He washed his car.
His car was washed.
I was given money only by my parents.
Only my parents gave me money.
He's being held in a cell.
They/some one/somebody
She is making a chocolate cake.
A chocolate cake is being made.
That question has to be asked by at least one of us.
At least one of us has to ask that question.
Awards are given to those who deserve it by the committee.
the committee
They widened the road.
The road was was widened.
I am excited by small things.
Small things excite me.
I did the housework and the house is now totally clean.
I
No one knows why the accident happened.
Why the accident happened is not known.
This was developed.
They/someone developed this.
The news was spread through newspapers.
newspapers
Someone has already told that story.
That story has been told.
The weather can't be controlled.
Nobody/no one can control the weather.
Medals were given to the winners by the referee.
The referee