第22题: [单项选择]The meeting was so prolonged and exhausting that ______ the speakers stopped for refreshments. A. at large B. at ease C. at intervals D. at random 参考答案:C 答案解析:[解析] 此题考查介宾短语的含义。 [详细解答] at intervals意为“不时,偶尔”,符合本题题意。at large作“详尽地,仔细地”讲,at case意为“安逸,自由自在”;