第29题: [单项选择]Sub-Saharan African countries ______. A. will have the largest world population by 2020 B. have the highest reproductive rate in the world C. are only modestly affected by AIDS D. will have increasingly long life spans 参考答案:B 答案解析:细节题。从文章的第三段可以看出亚萨哈拉非洲国家的人口出生率是世界上最高的。