1. I'm often invited to their parties. 2. English is spoken in different parts of the world. 3. Milk is used for making butter. 4. Passive Voce is formed with help of auxiliary verb "to be ".5. A lot of new houses are built in this district every year. b)1. This house was built in 1950.2. The front door was locked by somebody. 3. My pen was broken last night. 4. The boy was punished for that. 5. The work was finished in time. c)1. It will be forgotten by people. 2. This book will be translated next year. 3. You'll be told when to come. 4. Where will be built the new library? 5. He will be asked about it.