Change active into passive voice.
1. Columb us discovered America.
2. Someone is helping her with her work
3. The queen will open the museum
4. They built the church in the 15th centure
5. The postman clelivers letters in the morning
6. They speak English in Australia
7. Someone has broken the vase
8. He is writing a book now
9. You may open the window
10. Popov invented radio