A:Really
B:Obviously
C:Actually
D:Exactly
没有错别字的一组是 ( )
(Ⅰ)若f( π6 )=2,求a的值;
(Ⅱ)若f(x)在 π12 , 7π12 上单调递减,求f(x)的最大值.
In the last few years, China ___ great achievements in environmental protection.