The surgeon suggested that he at once.
A. needed operating on
B. needed operation
C. need operating on
D. need to be operated
网友回答
A. needed operating on
B. needed operation
(答案→)C. need operating on
D. need to be operated
解析：通过分析句子结构，可知这个句子中包含一个宾语从句，并且是suggest之后的宾语从句，suggest在这句话中意思是“建议”，所以宾语从句中要用“ should + 动词原形”，should可以被省略的虚拟语气。