1-This flower is watered by my father every morning
2-Fiona was invited to John's birthday party by him last night
3-The dinner is being cooked in the kitchen by her mother
4-Our teeth will be cleaned twice a day
5-The English grammar has been explained by our teachers

6-The accident in this city was caused by some drunk drivers
7-Tom's parents must be visited by him next month
8-The cookies were eaten in the room