part of,parts of 2个词的区别?

part of,parts of 2个词的区别? a part of,part of,parts of三个词有什么区别? a part of,part of,parts of三个词的区别? the part of和the parts of 的区别 是most part of还是most parts of? Part of 和a part of 和parts of的区别 the northern parts of China 为什么part是复数形式 one of the parts 这个part 为什么要加s We were all part of it.用part 还是parts还是a part. become part of 和 become a part of这两个词组都对吧?没有become parts only ------the surface of the earth is land.A.part of B.a part of C.parts of D.part 选什么为什么 Having been used for many years,__ of the road is broken.1 part 2 a part 3 parts 为什么要选1而不选2 , To make an orange dye,3parts of red dye are mixed with 2parts of yellow dye.To make a green dye,2parts of blue dye are mixed with 1part of yellow dye.If equal amounts of green and orange are mixed,what fraction of the new mixture is yellow dye? PART OF part of parts of the world problems are parts of lift parts of trucks.