a whom the nurse is talking b which the nurse is talking to
c the nurse is talking to him d the nurse is talking to
參考答案:选 D
这里是考察定语从句， 先行词是the doctor， 从句中主语是the nurse
谓语是 is talking to,所以这里是需要一个宾语，由于doctor是人，所以只能who和whom，这样就排除了 B， A选项中 talking是不及物动词，不能够直接接宾语，所以排除， C 选项中其实引导词就相单于句子的him（the doctor），所以也排除， D中只是省略了引导词whom， 因为是做宾语，可以省略，做主语则不能省略。
