单选题 As the headmaster made a long speech, the ceremony was prolonged by ten minutes.
【正确答案】 D
【答案解析】[解析] 本句意思：由于校长发表了很长的讲话，典礼被延长了十分钟。prolong意思是“延长”，与lengthen(使变长)意思相近。quicken加快，加速；enlarge扩大，增大；enrich充实，使丰富。