单选题 The students were told to make ______ study of the air situation in ______ city of Beijing.
【正确答案】 B
【答案解析】[解题指要] 该题测试冠词的用法。make a study of指对某个题目或学科做出某种程度的研究,如make a study of Chinese literature研究中国文学。the city of Beijing特指北京城,故city应与定冠词the连用。