语法与词汇 6.The discussion was so prolonged and exhausting that______the speakers stopped for refreshments.
【正确答案】 B
【答案解析】A项at large意为“逍遥法外;未被捕获”;B项at intervals意为“不时,时时”;C项at ease意为“自在,合适”;D项at random意为“任意,随机”。