One source of anger is failed attempts to change in the past. （People become so frustrated by earlier efforts that they can actually become mad when you point to an important new issue.）
【正确答案】：先前的努力白费了，人们沮丧不已。倘若你又提出新的重要问题，他们可能会发疯。
【题目解析】：point to翻译成‘提出”；an important new issue翻译成“新的重要问题”；become mad翻译成“发疯”。
