`1`  His excercis e was finished by him on time 

`2`  Rice is planted in people's fields.

`3`  Cars and trucks are used to carry food to markert 

`4`  My window was broken by the boy yesterday.

`5`  He has been known well.

`6`  He will be met at the station 

`7`  Was your test done Perfectly ? 

`8` Why wasn't this lesson learned ? 

`9`  How long has their work been done? 

`10`  He wasn't helped by noone.

1. He finished his exercise on time.

->his exercise was finished on time.

2. People plant rice in those fields.

->rice is planted in these fields.

3.They use cars and trucks to carry food to market.

->cars and truckss are used to carry food to the market.

4.This boy broke my window yesterday.

->my window was broken by this boy yesterday.

5. They have known him well.

->He has been known well.

6. We will meet him at the station.

->he will be met at the station.

7.Did you do your test perfectly?

->Was your test done perfectly ?

8. Why didn't you learn this lesson?

->Why wasn't this lesson learnt ?

9.How long have they done their work?

->How long has their work been done ?

10.No one could help him.

->He couldn't be helped.