单选题 People can (not) but feel (puzzling), for they (simply cannot) understand how he (could have made) such a stupid mistake.
A. not B. puzzling C. simply D. could have made

【正确答案】 B
【答案解析】[解析] 应改为puzzled。当形容人时常常用puzzle的过去分词形式puzzled，puzzling常用来形容事物。