1. My parents should allow me to study with friends.（改为同义句）
    I should _________ _________ to study with friends.
2. They often 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.

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.