1. My parents should allow me to study with friends.(改为同义句) I should ______ ______ to study with friends. 2. They oft en clean their classroom after school. (改为被动语态) Their classroom ______ often ______ by them after school. 3. Li Lei gave Tom a new pen last week. (改为被动语态) A new pen ______ ______ ______Tom last week. 4. It took him ten years to finish writing the book. (改为同义句) He ______ ten years ______ the book. 5. They will publish these story-books next month. (改为被动语态) These story-books ______ ______ ______ next month.