单选题 He had a clear ______ of what was wrong with the machine and fixed it in a short time.
A. debris B. deficiency C. perception D. persecution

【正确答案】 C

【答案解析】[解析] 本句是说他非常清楚机器出了什么毛病，一会儿就把它修好了。perception“理解，感知”与句意相符。而debris“碎片，残骸”；deficiency“缺乏，不足”；persecution“迫害”都不正确。