根据要求完成句子。

1. Whatever he did, he could do best. (改为同义句)

    _______ _______ what he did, he could do best.

2. I know the boy. He speaks English well. (改为复合句)

    I know the boy _______ _______ English well.

3. I hope that I can visit Beijing some day. (改为同义句)

    I hope _______ _______ Beijing some day.

4. My brother is not old enough to join the party. (改为同义句)

    My brother is _______ ______ to join the party.

5. We clean our classroom twice a day. (改为被动语态)

    Our classroom _______ _______ twice a day.