1-6.CCABCA 7-12.BDDBCC 13.[2,3] 14.[5,10] 15. 16.4
17. 18.(1)a=8,sinC=(2) 19.(1)(2)
20.(1)(2)0.4
21.(1)a=0.5(2)g(x)在上递减,在,
22.(1)(2)