单选题 A ______ surgeon can be as dangerous as a recruit with a gun who does not know how to handle.
A. professional B. negligent C. competent D. mellow

【正确答案】 B

【答案解析】[解析] professional“专业的”；negligent“疏忽的，粗心大意的”；competent“胜任的，有能力的”；mellow“成熟的，圆润的”。由题意可知，正确答案为B。