按要求转换句型。

1. I have already packed the camera.(改为否定句)

    I _____ _____ the camera _____. 

2. We are ready.(改为一般疑问句)

     _____ you _____? 

3. I have locked the window.(改为一般疑问句)

    _____ you _____ the window?

4. She has cleaned her room.(改为否定句)

    She _____ _____ her room.

5. What about your brother?(改为同义句)

     _____ _____ your brother?

简述苏轼散文赋作的散体特征。