change these sentences into passive voice. 1. Suman has knocked the door. 2. She has mailed the postcard. 3. They have written a poem. 4. Anita had cleaned her room. 5. The villagers are going to build a temple. 6. Anu should cook food

1 ) The door has been knocked down by Suman

2 ) The postcard has been mailed by her

3 ) A poem has been written by them

4 ) Her room has been cleaned by Anita

5 ) A temple will be built by the villagers

6 ) Food should be cooked by Anu

not concrete, existing in thought or as an idea but not having a physical or concrete existence