China is the world's most populous country with a population of 1.1 billion, which makes up（ ）a quarter of the world population.
A、precisely
B、merely
C、substantially
D、approximately
【正确答案】：D
【题目解析】：本题考查副词辨析。precisely“精确地”， merely“仅仅”，substantially大量地”， approximately“大约”。句意：中国是世界人口最多的国家，有11亿，约占世界总人口的四分之一。故选D。
