Primero en vos activa para que tengas las oraciones bases ^-^:
1) The teacher buys a car
2) Sonia wrote a letter
3)Jhon and Tony have donde the landscape
4) The Doctor is going to fix the truck
5)Rocio will steel the market
6)Ricardo dream whit Death note 
7)Carlos will sing a romantic song
8)Davinci painted the Mona Lisa
9)Xiomara kisses Juanma
10) Hector understand the topic
y ahora las mismas 10 pero en pasivas :
1)The car is bought by the teacher
2)The letter is wroten by sonia
3)The landscape has been done by Jhon and Tony
4) The truck is going to be fix by the doctor
5)The market will be steel by Rocio
6)Death note was dreamed by Ricardo
7)A romantic song will be sing by Carlos
8)The Mona Lisa was pinted by Davinci
9)Juanma is kissed by Xiomara
10)The topic is understood by Hector