What does John do on the farm?Oh,his job is _____ the animals.

题目

What does John do on the farm?Oh,his job is _____ the animals.
选项有 A.to feed B.feed C.to feeding 答案是选A..但是我总觉得应该选B的..为什么啊...

答案

答案：A
动词不定式作表语.
句意：约翰在农场上做什么（工作）?噢,他的工作是喂牲口.