A:looked
B:was looking
C:have been looking
D:had been looking
两位数乘一位数,积一定是两位数.
____ 是日本人的传统服装.
定义域为R的偶函数fx满足对∀x∈R,有fx+2=fx-f1,且当x∈2,3 时,fx=-2x2+12x-18,若函数y=fx-logax+1在0,+∞上至少有三个零点,则a的取值范围是( )