43. The mad dog bit the little boy.
The little boy was bitten by the dog
44. The police have arrested five suspects.
→Five suspects have been arrested by the police
45. They didn't allow Tom to take these books home
→  Tom wasn't allowed to take these books home by them
46. The teacher won't correct exercises tomorrow.
→ Exercises won't be corrected by the teacher tomorrow
47. Marry has operated Tom since 10 o'clock.
→ Tom has been operated by marry since 10 o'clock
48. Mr. Smith has taught us French for two year.
→ We have been taught French for two year by Mr. Smith
49. They didn't look after the children properly.
→ The children weren't looked after properly by them
50. People spend a lot of money on advertising every day.
→  A lot of money is spent on advertising every day