21. The education of _______ young has become _______ hot and serious topic in the present society.
A. the; / B. a; the C. /; the D. the; a
选D。考查冠词的用法。the加上形容词表示一类人或物。句意：年轻人的教育问题已成为目前社会中的一个热门而又严肃的话题。故选D。
22. The _______ report was completed in less than one day—six hours, to be more exact.
A. latest B. urgent
C. scary D. unfortunate
