根据要求改写句子

问题描述:

根据要求改写句子
1. He hoped that he could pass the English exam. (改为简单句)
2. Jack heard that the girl sang a song just now. (改为简单句)
3. I don't know how I should do it. (改为同义句)

he hoped to pass the English exam.
Jack heard the girl singing a song just now
I don't know how to do it