从A、B、C、D四个选项中，选出可以填人空白处的最佳选项，并在答题卡上将该项涂黑。
例：It is generally considered unwise to give a child he or she wants.
A. however B. whatever C. whichever D. whenever
21.Instead of having to choose one or the other, we can adopt _____of the approaches.
A. some B. both C. all D. another
22.I soon found that the work I was doing had already been finished by someone,_____I was wasting my time.
A. in no sense B. on the contrary C. by the way D. in other words
23.China’s education reforms aim to better develop students’ ability to think_____.
A. independently B. steadily C. negatively D. particularly
24.Because of H7N9, all the chicken markets in Shanghai have been closed and won’t open until further______
A. sign B. symbol C. contact D. notice
25.Our government’s plan to fight against air pollution will focus on _____ information and
handling PM2.5.
A. expressing B. representing C. gathering D. acknowledging
