单选题 General anesthesia, which is usually used for major surgery, involves a complete loss of consciousness and a relaxed of the muscles.

【正确答案】 C

【答案解析】答案：C 分析：名词和形容词误用，relaxed是过去分词做形容词。改正：relaxedàrelaxation。翻译参考：全身麻醉通常用于大型外科手术，它使知觉完全丧失，肌肉得到放松。