第23题: [单项选择]The professor found himself constantly ______ the question: "How could anyone do these things" A. presiding B. poring C. pondering D. presuming 参考答案:C 答案解析:[考点] 考查动词词义辨析。 preside意为“主持”;pore表“钻研”时,为不及物动词,常与on,over连用;ponder意为“沉思,仔细考虑”;presume意为“假定”。根据句意