The sentence(s) in Passive Voice

Варианты ответа

1. A.America was discovered by Christopher Columbus.верно
2. B.Put the bum under cold water.
3. C.The least is said, the more is done.верно
4. D.Storms around the world cause much damage.
5. E.Because of toothache I was taken to the dentist.верно
6. F.Warm milk helps you to go to sleep.