49. They have to repair the engine of the car.
the engine of the car has to be repaired 
50. The boysbroke the window and took away some pictures.
the window was broken and some pictures were taken away by the boys 
51. People spend a lot of money on advertising everyday.
a lot of money are spent on advertising everyday 
52. They may use this room for the classroom
this room may be used for the classroom 
53. The teacher is going to tell a story
a story is going to be told by the teacher 
54. The children looked at the women with a hat
the women with a hat was looked by the children