Passage 1：46-50 BBACD
46. What do we learn from the passage about cities in sub-Saharan Africa?
B）They are growing fast without becoming richer
定位：第一段第二句及第四句。第二句What’s indisputable is that it’s growing very quickly对应growing fast, 第四句sub-Saharan Africa are not getting richer the way cities in the rest of the world have.
47. What does the author imply about urbanisation in other parts of the world?
B) It started when people’s income was relatively high.
定位：第二段第二句：Most of Africa is urbanizing at a lower level of income than other regions of the world did.下文又提到因为收入低，所以缺少投资的钱。
48. Why is sub-Saharan Africa unappealing to investors?
A) It lacks adequate transport facilities.
定位：第二段最后一句:… the only light rail metro system…keep investors away.
49. In what way does author say African cities are different?
C) They have developed at the expense of nature.
50. What might be a solution to the problems facing African cities?
D) A more responsible government