of which后加什么
`which of` 后面应该跟名词。这个结构用于询问在某个范围或群体中哪一个元素或个体。例如：
Which of the books do you like best？ 你最喜欢哪本书？
Which of the new releases do you think are really good？ 你认为这些新片中哪些真的不错？
The customer and vendor will decide between them which of these tests will be used in their purchase contract. 客户和供应商将在他们之间决定这些测试中哪一个将被用于他们的购买合同
