In some developed countries, larger population is in their big cities.
A. approved
B. gathered
C. concentrated
D. fixed
网友回答
A. approved
B. gathered
(答案→)C. concentrated
D. fixed
解析：考察动词词义辨析。A批准；赞成；B聚集，采集；C集中；D维修，修理；句意：在一些发达国家，大量的人口都集中在大城市里。根据句意说明C项正确。