Nobody swept this street yesterday. Somebody has already told her the whole truth

1/ Nobody swept this street yesterday.
->This street
2/ Somebody has already told her the whole truth.
->She
3/ The police found two children in the forest, didn't they?
->Two children
4/ A thief had stolen her car before you arrived.
->Her car
5/ They used to start these engines by hands.
->These engines
6/ No one has seen Steve since the day of the party.
->Steve
7/ The manager has the typist type the letter.
->The manager has
8/ A young man sent those letters for me.
->I had
9/ You ought to water the plants every day.
->The plants
10/ People had reported the accident before I phoned.
->The accident
11/ Tom has just invented an armchair which can play music.
-> An armchair
12/ We are going to take our children to the zoo next Sunday.
-> Our children
13/ Dangerous driving cause many accidents.
-> Many accidents
14/They didn't hold a meeting in the village hall last week.
->A meeting
15/ The scientists are studying the problem very carefully.
->The problem