副词的用法：
1.修饰动词
listen carefully(carefully为副词）
2.修饰形容词
too much home work（too为副词）
3.修饰整句话.其中有些连词也可以作副词,比如thought,since,in case等,放在句末.
Obviously,she didn't finish it.(obviously为副词修饰整句话）明显她没有完成.