生化仪的定标步骤:为什么答案是which one to choose,而不是to choose which one?

为什么答案是which one to choose,而不是to choose which one? I can't decide to buy which one, 翻译:which one do you want to buy? 翻译:which one don't you want to buy? how to translate it,and which one is fault 答案为什么是C？ It was last night_____ I saw the comet. A.the time B. when C.that D.which 答案是C，能否选B为什么 It was last night_____ I saw the comet. A.the time B. when C.that D.which 答案是C,能否选B?为什么? 请分析此句句子成分"It is an intellect to which one still listens."“to which"和"one"什么关系？ Which one is right?