The cause of Mozart's demise is a long-standing medical______. Over the years, physicians have suggested more than 100 possibilities, including poisoning, malnutrition, kidney disease, and heart failure.
【正确答案】
A
【答案解析】解析：选项A为“秘密，谜，神秘，神秘的事物”；选项B为“争论，争执”；选项C为“公开辩论，论战”；选项D为“试验，审讯，审判”。由后半句中提供的信息，“莫扎特的死亡有一百多种可能性(physicians have suggested more than 100 possibilities)”，可以判断莫扎特之死是一个“不解之谜”，故选A。