1. They are repairing the streets this month

=> The streets are being repaired by them this month.
2.They make these tools of plastic

=> These tools of plastic is made by them.
3. They have finished the new product design

=> The new product design has been finished by them.
4. They were cooking dinner when I arrived

=> Dinner was being cooked by them when I arrived.
5. Smithers painted 'Red Sunset' in 1986

=> Red Sunset' was painted by Smithers in 1986
6. Did the plan interest you?

=> Was you interested by the plan ?
7. They had finished the preparations by the time the guests arrived

=> The preparations had been finished by the time the guests arrived.
8. He left the briefcase on the counter

=> The briefcase was left on the counter by him
9. Helen took the newspaper on the table an hour ago

=> The newspaper was taken by Helen on the table an hour ago
10. She will write a report to the director this afternoon

=> A report will be written to the director this afternoon by her