问题
选择题
The population of Africa is ________ so rapidly as to cause concern of the whole world.
A．expanding
B．circulating
C．exporting
D．spreading
答案
答案：A
动词辨析。句意：非洲人口在快速增长，引起了世界的关注。expand：扩张、发展；circulate：循环；export：出口；spread：扩散。