第二部分 知识运用（共两节，45分）
第一节 单项填空（共15小题；每小题1分，共15分）
从每题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21.The study, in the online edition of the journal Brain, showed that after one year of musical training, children performed better in a memory fest than who did not take music classes.
A. published; those B. publishing; these
C. to be published; ones D. being published; the ones
22. its suicide rate double in less than a decade, the country will also set up more counseling centers and try to increase awareness of the risks of depression.
A. Having seen B. Seeing C. To see D. Seen
23.Even though be gives away a piece of his fortune each year, the stock of Berkshire Hathaway, the source of Warren Buffet’s wealth, very rapidly.
A. has raised B. has been raising C. has risen D. has been rising
