单选题 After speaking for three hours, the lecturer found he could scarcely talk, as he had become ______.

【正确答案】 C
【答案解析】dumb哑的，无说话能力的；inarticulate不善言辞的；hoarse嘶哑的；speechless不能说话的。演讲者话讲的太多了，以至于嗓子嘶哑说不出话来。