Помогите решить Passive voice

Ответы на вопрос
Ответ:
2. Your test will be marked by Mrs Richard
3. the murder had been reported by neighbour
4. The thief was seen by an old lady
5. the office is locked every evening by Mr Jones
6. a new species of dinosaur has been discovered by scientists
7. the article for next week's issue will be written by Isabella
8. The Parthenon was built by ancient Greeks
Ответ:
2 Your tests will be marked by Mrs Richards.
3. The murder had been reported by a neighbour.
4. The thief was seen by an old lady.
5.The office is locked by Mr Jones every morning.
6. A new species of dinosaur has been discovered by scientists.
7.The article for the next week's issue will be written by Isabella.
8.The Parthenon was built by the ancient Greeks.
Объяснение: