Mrs Green are very grateful to the neighbour helped her child out of the fireA. whichB.

问题补充：

Mrs Green are very grateful to the neighbour helped her child out of the fire．

A. which

B. what

C. who

D. how

答案：

A. which

B. what

(答案→)C. who

D. how

解析：根据语境可知此句的先行词是the neighbor是人，且在从句中做主语故选who，故选C。