1 A nice present was bought by Tom yesterday

2 My computer was repaired by Ben yesterday

3 An SMS was sent to Tim's friend by him

4 This museum was visited by them yesterday

5 The rule was explained by our teacher

6 The candle is put on the table by him

7 The vase was dropped by the cat yesterday

8 A long letter was written by you yesterday

9 A magazine was not bought by me last weekend

10 Several candidates were called for a second interview by Mr Brown

Ex 8: 1, A nice present was bought by Tom yesterday

2, My computer was repaired by ben yesterday

3, An SMS was sent to his friend by Tim 

4, That museum was visited yesterday

5, The rule was explained by the teacher

6, The candle was put on the table by him

7, The vase was dropped by the cat yesterday

8, A long letter was written by you yesterday

9, A magazine wasn't bought by you last weekend

10, Several candidates were called for a second interview by Mr. Brown