don't know what is the difference between them”和“I don't know what the differ

ence between them is" .这两句话哪个对啊?I DON'T KNOW WHAT THE MEANING OF THE WORD IS 是
I DON'T KNOW WHAT IS THE MEANING OF THE WORD .这句话也是这种情况.关键是什么呢?what is the difference中的what是是成分?答案解析：宾语从句必须用陈述语序
因此,答案为：I don't know what the difference between them is 为正确答案
主句主语：I （我）
主句谓语：don't know （不知道）
引导宾语从句连接代词：what （什么）
从句主语：the difference （区别/ 差别）
从句修饰主语定语：between them （在它们之间的）（介词短语做后置定语）
从句系动词：is （是）
从句表语：what （什么）
整个句子中文意思：我不知道她们之间的区别是什么.