part of和a part of有什么区别?

part of和a part of有什么区别? part of 和a part of有何区别? part of 和a part of有何区别? a part of 和 part of 有什么区别呢?该怎么用呢? a part of +什么名词 a part of,part of,parts of三个词有什么区别? a part of them 和part of them哪个对 part of和a part of的区别? as a part of和as part of一样吗? part of 与 a part of全部的区别a part of 和 part of的区别,要全的, a part of the part of part of 区别 a part of与part of的用法有什么区别 in the southern part of 和in the south part of 有什么区别? a part of 和part of有什么区别吗?还有parts of,这几个短语有什么区别?能不能给我一些例句啊 A small part of 请问a part of和part of的区别在课外阅读上经常看到的是part of而不是a part of,part应该是可数名词吧,如果不加不定冠词a也应该加个定冠词the吧,那它们有什么区别?ps:刚才稍微查了一下,有人说a part PART OF part of