1. The story made me feel sad．(改为被动语态)
    I _________ _________ _________ _________ sad by the story.
2. The boy usually went to school late.(改为同义句)
    The boy _________ _________ _________ to school late.
3. The river has been polluted by the factory since five years ago.(改为主动语态)
    The factory _________ _________ the river since five years ago.
4. We're trying to save the manatees.  (对画线部分提问)
    _________ _________ you trying to _________ ?
5. Manatees eat about 100 pounds of food a day．(改为一般疑问句)
    _________ manatees _________ about 100 pounds of food a day?