$\text{⇒ Answer:}$

$\text{1. A short circuit in the lift machine was believed to have}$

$\text{caused the fire.}$

$\text{2. Their marroage was decided to have been organised in}$

$\text{December.}$

$\text{3. It is known that she is a good swimmer.}$

$\text{4. It is said that Francis is in hospital.}$

$\text{5. It is thought that the children are in bed.}$

$\text{6. It is believed that the robber has worked in the bank.}$

$\text{7. It is believed that nuclear powere stations are dangerous.}$

$\text{8. It is thought that he was on holiday by his colleagues.}$

$\text{9. It is known that cars pollute the inviroment.}$

$\text{10. It is supposed that the new product will come}$

$\text{out soon.}$

$\text{11. The mission was found to be impossible.}$

$\text{12. She is believed to win a gold medal.}$

$\text{13. The expedition is known to have reached the South Pole}$

$\text{ in May.}$

$\text{14. The company is believed to have lost a lot of money.}$

$\text{15. The earth is believed to have stood still.}$

$\text{16. It is believed that 13 is an unlucky number.}$

$\text{17. It is rumored that the man was still living.}$

$\text{18. It is thought that he has died a natural death.}$

$\text{19. It was thought that Tom was the laziest of all the pupils.}$

$\text{20. It is rumour that he has gone to Canada on some}$

$\text{important business.}$

$\text{21. It was said that he was nice to his friends.}$

$\text{22. It was said that he had been nice to his friends.}$

$\text{1. It was believed that the fire was caused by a short circuit in}$

$\text{the lift machinery.}$

$\text{⇒ A short circuit in the lift machine was believed to have}$

$\text{caused the fire.}$

$\text{2. It was decided that their marriage would be organised}$

$\text{in December.}$

$\text{⇒ Their marroage was decided to have been organised in}$

$\text{December.}$

$\text{3. People know that she is a good swimmer.}$

$\text{⇒ It is known that she is a good swimmer.}$

$\text{4. They say that Francis is in hospital.}$

$\text{⇒ It is said that Francis is in hospital.}$

$\text{5. They think that the children are in bed.}$

$\text{⇒ It is thought that the children are in bed.}$

$\text{6. People believe that the robber has worked in the bank.}$

$\text{⇒ It is believed that the robber has worked in the bank.}$

$\text{7. People believe that nuclear power stations are dangerous.}$

$\text{⇒ It is believed that nuclear powere stations are dangerous.}$

$\text{8. His colleagues thought that he was on holiday.}$

$\text{⇒ It is thought that he was on holiday by his colleagues.}$

$\text{9. People know that cars pollute the environment.}$

$\text{⇒ It is known that cars pollute the inviroment.}$

$\text{10. They suppose that the new product will come out soon.}$

$\text{⇒ It is supposed that the new product will come}$

$\text{out soon.}$

$\text{11. They found that the mission was impossible.}$

$\text{⇒ The mission was found to be impossible.}$

$\text{12. They believe that she will win a gold medal.}$

$\text{⇒ She is believed to win a gold medal.}$

$\text{13. We know that the expedition reached the South Pole in May.}$

$\text{⇒ The expedition is known to have reached the South Pole}$

$\text{in May.}$

$\text{14. People believe that the company is losing a lot of money.}$

$\text{⇒ The company is believed to have lost a lot of money.}$

$\text{15. People believed that the earth stood still.}$

$\text{⇒ The earth is believed to have stood still.}$

$\text{16. People believe that 13 is an unlucky number.}$

$\text{⇒ It is believed that 13 is an unlucky number.}$

$\text{17. They rumored that man was still living.}$

$\text{⇒ It is rumored that the man was still living.}$

$\text{18. They think that he has died a natural death.}$

$\text{⇒ It is thought that he has died a natural death.}$

$\text{19. Everyone thought that Tom was the laziest of all}$

$\text{the pupils.}$

$\text{⇒ It was thought that Tom was the laziest of all the pupils.}$

$\text{20. They rumour that he has gone to Canada on some}$

$\text{important business.}$

$\text{⇒ It is rumour that he has gone to Canada on some}$

$\text{important business.}$

$\text{21. People said that he was nice to his friends.}$

$\text{⇒ It was said that he was nice to his friends.}$

$\text{22. People said that he had been nice to his friends.}$

$\text{⇒ It was said that he had been nice to his friends.}$