Tony wanted to know what Father Christmas had put in his stocking.
A. what had Father Christmas put in his stocking
B. when Father Christmas had put in his stocking
C. what Father Christmas had put in his stocking
D. where Father Christmas had put in his stocking
这里我选的 D，为何是错的?

参考译文：托尼想知道圣诞老人在他的袜子里放了什么？

完整的答案解析以及解答如下：

以上属于：非谓语动词中的“不定式”+宾语从句 结构，从语法上讲，根据宾语从句需要用陈述语序，因此A答案是不正确的，在根据宾语从句的谓语动词put属于及物动词，需要接宾语，所以排除了BD,最后就只有C是正确答案了。

判断一个英语句子是否正确必须满足以下2点

(1)语法必须要正确

A:句子时态要正确

B:句子语态要正确

C:句子语气要正确

D:句子主谓一致要正确

E:句子一些固定搭配要使用正确

F:句子结构必须要完整且正确(即句子成分必须有，不能缺少）

(2)句子语义必须正确

A:句子意思要说得通顺

B:句子意思要符合逻辑

    know 是及物动词，后面的句子应该是宾语从句。宾语从句应该用陈述句的语序。在 A. what had Father Christmas put in his stocking中，助动词 had 放在主语Father Christmas的前面，属于疑问句的语序，所以 A.是错误的。put (放)是及物动词，应该有名词中代词作宾语，when 是时间状语，就是说，B. when Father Christmas had put in his stocking 项没有宾语，所以是错误的；where可以作地点状语，不能作宾语，所以D. where Father Christmas had put in his stocking 也是错误的。所以，只有C. what Father Christmas had put in his stocking才是正确的。