按要求变化下列各句。

1. She walked so slowly that she missed the last bus. (改为并列句)

    She walked _____ slowly ____ catch up with the last bus.

2. I forgot everything. So did Tom. (改为同义句)

   ____ Jim ____ I couldn't ____ everything.

3. Have you visited the Great Wall? Cold you tell me?

   Could you tell me ____ you ___ visited the Great Wall?

4. Work hard, or you'll fall behind others. (改为同义句)

    ____ you ____ work hard, you will fall behind others.

5. The math problem is too difficult for him to work out. (改为复合句)

    The math problem is ____ difficult ____ he can't work out.