Biến đổi câu chủ động thành câu bị động: My dad is waters this flower every morning; John invited Fiona to his birthday party last night; Her mother is preparing the dinner in the kitchen

1, My dad is waters this flower every morning 
2, John invited Fiona to his birthday party last night 
3, Her mother is preparing the dinner in the kitchen 
4, We should clean our teeth twice a day 
5, Our teachers have explained the English grammar 
6, Some drunk drivers caused the accident in this city 
7, Tom will visit his family next month 
8, The manager didn't phone the secretary this morning 
9, Did Mary buy this beautiful dress?
10, I won't hang these old pictures in the living room 
11, The waiter brings me this dish
12, Our friends send these postcards to us 
13, Their grandmother told them this story when they visited her last week 
14, Tom ordered this train ticket for his mother 
15, You didn't show me the special cameras