Change the following active constructions into passive ones. 1. They were writing the letters, when I entered the room. 2. We had built a new library in the city. 3. They are performing a new piece of jazz. 4. They have designed new scenery for the play.

Last Friday me and my mom went shopping. I wanted to buy a winter coat for myself. As I walked into the store I noticed my mom talking with some guy. He didn't look like he was shop assistant. It was really strange, because I've never seen him before.
I came closer and then that guy looked at me. 
"Oh my God, you're grown up already!" Said that man with a smile on his face.
"That's your uncle Sasha." said mom.
"Oh, you don't remember me?" The guy looked into me eyes and smiled. 
"I don't" I answered. 
"It's ok. You were really small when we've last met." He said. "So I need to go." 
"Goodbye" we said.

1) When I come home, I will call you. 2) If I see him tomorrow, I will give him this book. 3) He will be glad if we tell him about it. 4) We are going to Paris next week, that's why we are buying tickets now. 5) I hope that they will be at home tomorrow. 6) When will he call? He will call as soon as he gets time. 7) Tomorrow my sister will go to the cinema if she buys tickets. 8) If you go shopping, buy me some coffee. 9) When she comes to school, she will listen teacher attentively. 10) He will agree if we invite them to the theatre. 11) I can't stand him talking like this. 12) Listen how well she is singing. She will stop singing if she hears you talking. 13) She often watches TV, but now she is not watching it, she is reading a book. 14) My brother is not at home now. Leave him a note. 15) Send me a letter if you go to Germany. 16) When I need help, I will ask them to help me. 17) He must finish his business before he leaves. 18) Do you still hope that they will call you? 19) She thinks that we will help her as soon as we can. 20) If you find my keys, return them to me.