Transform the following sentences from the Active into the Passive.
Model: They often read this book. (Active Voice) This book is often read. (Passive Voice)
1. They read this book yesterday. (Active Voice)
2. They will read this book tomorrow. (Active Voice)
3. They are reading it now. (Active Voice)
4. They have already read this book. (Active Voice)
5. They had read it by two o'clock. (Active Voice)
6. They will have read it by Sunday. (Active Voice)