Empire of the sums

url: http://www.economist.com/news/books-and-arts/21613162-mass-immigration-chinese-people-africa-almost-entirely-driven-money

1. "ni hao" and 'chi ku'  may be the two commonest phrases

           commonest phrases 最常见的短语

2.  reckon:  establish by counting or calculation

     Mr French reckons that 

            reckon 估计

3.  What is clear, at any rate, is that Chinese people and money have flooded into Africa in the past decade

          * what is clear is that  “清楚的是”  当不知道用什么当主语时，可用what 来开头

          * flood into 涌进