有一个语法题,说水晶是结构很复杂的物质,有millions upon millions atoms, 逗号后开始划线,考的是each结构和介词搭配。 选项有,each holding a fixed position of a XXXX structure each held in a fixed position within a XXXX structure等等,总之考的是each holding a position 还是each held in a postion, 是position of structure 还是within structure,大家可以确认一下这两个到底怎么用。