1、若数列{an}满足a1=2,a2=3,an=(n≥3且n∈N*),则a2 018=(  )
A.3 B.2C.     D.
2、经过点P0(2,-3),倾斜角为45°的直线方程为(  )
A.x+y+1=0                                                                   B.x+y-1=0
C.x-y+5=0                                                                    D.x-y-5=0
3、已知点(a,2)(a>0)到直线l:x-y+3=0的距离为1,则a等于(  )
A.B.2-C.-1                                                 D.+1
4、从1,3,5中取两个数,从2,4中取一个数,可以组成没有重复数字的三位数,则在这些三位数中,奇数的个数为(  )
A.12 B.18C.24                                                             D.36
5、在等差数列{an}中,a1+a5=10,a4=7,则数列{an}的公差为(  )
A.1        B.2        C.3                      D.4
6、顶点在原点,对称轴为坐标轴,且过点P(-4,-2)的抛物线的标准方程是(  )
A.y2=-x                                                                         B.x2=-8y
C.y2=-8x或x2=-y                                   D.y2=-x或x2=-8y