Put the sentences into passive voice. Mind the tenses.
The thunderstorm damaged some houses.
by the thunderstorm.
George and Bill sell old cars.
by George and Bill.
Jack the Ripper killed many women.
by Jack the Ripper.
George collects stamps.
Cole Porter composed some nice musicals.
by Cole Porter.
Your products impressed us.
by your products.
Mrs. Smith wore these pearls last Christmas.
by Mrs. Smith last Christmas.
Mr. Important presented our new product at the fair.
by Mr. Important at the fair.
They will place a trial order soon.
Frank had done all exercises.