2.Does they are often taken to the cinema by Mr Green on Sunday?
3. Were the books returned to the library by them?

Passive voice
1. Many teachers often give the students much homework 
=> Much homework is often given to the students by many teachers.
2. Does Mr Green often take them to the cimema on Sunday?
=> Does they are often taken to the cinema by Mr Green on Sunday?
3. Did they return the books to the library? 
=> Were the books returned to the library by them?