单选题 7.  Until then did I realize that their marriage had ______ because they had little in common.
【正确答案】 C
【答案解析】[考点] 词义辨析
put off:推迟;give up:放弃;break down:失败,崩溃,(婚姻、恋爱关系)破裂;call off:取消。根据句意可知,选C。
   直到那时我才意识到他们的婚姻已经破裂,因为他们几乎没有共同之处。