1.若集合A={-3,-2,-1,0,1,2},B={xy=lnx},则An(CB)的元素个数为A.3B.2c.5D.4 m-5i2.若复数=1-1为纯虚数,则实数m的值为C.5 D.5A.-5B.5223.已知角a的起点在原点,始边与x轴的非负半轴重合,终边过点(5,-6),则tan2a= A.30B.-30c.60 D.60111111114.已知数列{an}的前n项和为S,且Sn+1=Sn+an+3,若a3=9,则S2=A.520B.53062015D.630