[解析]
答案:have suffered / have been suffering
考查时态.所给的动词suffer与主语Most parts of some African countries是主动关系,结合时间状语in recent years可知应用现在完成时或现在完成进行时,现在完成时的结构是has/have done,现在完成进行时的结构是has/have been doing,所以应填have suffered / have been suffering,故填have suffered / have been suffering.