47．B 【精析】该题为细节题。文中并未提到选项A表述的内容；根据第一段第五句“They had clearly defined rights，and their slave sta- tus was not necessarily inherited.”我们知道，非洲当地的奴隶拥有明确的权利，而且他们的奴隶身份不一定是世袭的，因此，我们可以判断出，奴隶的下一代不一定还是奴隶，B项正确；第一段第一句“For centuries the most valuable of African resources for Europeans were the salves, but these could be obtained at coastal ports．without any need for going deep inland．”告诉我们，运往欧洲的奴隶来自于海港地区，并没有指出非洲本地的奴隶制度只限于海港地区，故C项的表述是错误的；根据第一段倒数第三句 “Slavery in its extreme forms, including the taking of life, was common to both Africa and the West.”我们知道，屠杀奴隶的事件在非洲和西方国家都有发生，故D项的表述是错误的。