Помогите переделать в Passive Voice

1.We will close the window
2.They write letters every week
3.Bob has just spilt all the milk
4.Ann let in the dog
5.They suspect nobody
6.We'll keep the secret
7.I frightened my sister
8.Peter will meet Ann in the park
9.The teacher told the pupils to sit down
10.They didn't repair the bicycle
11.We won't take money
12.They didn't teave him alone